Worth it to swap out 750 eddy for a 750 double pumper?

[MoparMotel]

I posted a while back about swapping the stock 625 carter for a 750 edelbrock and while the car does run a lot better it just did not give me the performance gains I was hoping for. After seeing how an 850 double pumper performed on a friends 460 ford big block last night I wanted to see what your thoughts would be on if I would see any gains going to a 750 double pumper.

Engine is numbers matching 383 rebuilt 1,500 miles ago.
Mild build- 10:1 pistons, factory intake and Hp manifolds, comp cam .470 lift, and as of right now 2 1/4 dual exhaust with flowmaster 40 series with no H or X pipe.

Basically this car only gets driven once a week or sometimes every two weeks so fuel mileage isn't a concern, just trying to make the most power I can.
Right now this thing won't even break the tires loose and has the famous off idle edelbrock stumble.

Also... The flowmaster 40 series on the car are for 2 1/2" exhaust and I only have 2 1/4 piping so sometime this week or next week I'm going to have my exhaust guy run all new 2 1/2" piping and do an H pipe as well.

[Budnicks]

I posted a while back about swapping the stock 625 carter for a 750 edelbrock and while the car does run a lot better it just did not give me the performance gains I was hoping for. After seeing how an 850 double pumper performed on a friends 460 ford big block last night I wanted to see what your thoughts would be on if I would see any gains going to a 750 double pumper.

Engine is numbers matching 383 rebuilt 1,500 miles ago.
Mild build- 10:1 pistons, factory intake and Hp manifolds, comp cam .470 lift, and as of right now 2 1/4 dual exhaust with flowmaster 40 series with no H or X pipe.

Basically this car only gets driven once a week or sometimes every two weeks so fuel mileage isn't a concern, just trying to make the most power I can.
Right now this thing won't even break the tires loose and has the famous off idle edelbrock stumble.

Also... The flowmaster 40 series on the car are for 2 1/2" exhaust and I only have 2 1/4 piping so sometime this week or next week I'm going to have my exhaust guy run all new 2 1/2" piping and do an H pipe as well.

I would say yes go for it, I know a ton of guys love them Edelbrock Performer, Carter AFB AVS & THermoquad carburetors, they have their place...  I prefer the Holley type carburetors for performance use though, I have had better performance with them, even in a side by side carburetor Holley & Carter swap at the track comparison... On multiple 2x4 carbs & restorations, I do like the Eddy or Carters... Just prefer the Holleys for performance apps.      Just my opinion, I don't want any hate mail...

[Chryco Psycho]

Yes , Check out Proform carbs

[MoparMotel]

Looked around a little bit, is the one I should go with the #4150 which reads 750 double pumper? Also what are some more things to wake this car up? I am not very happy with it's performance....I think my Duramax diesel truck would walk away from this thing in a drag race. Maybe headers, intake manifold, ETC?

[Dino]

I'm still learning all this stuff, and will do so for a looooong time to come, but this is definitely the place to gain the knowledge!

I think that apart from the 2 1/2 h pipe some headers would give you some noticable gains.  383's are nothing to compare to modern engines but they are not exactly slow to begin with.  Come to think of it, those diesels do have a boatload of torque your 383 doesn't have. 

What's the rest of your setup?  What year Charger do you have?  What rear end and gears?  I lost a bunch of power going from 3.55 gears to 2.94 with a 440, but it is a lot more enjoyable to drive.

[Budnicks]

Looked around a little bit, is the one I should go with the #4150 which reads 750 double pumper? Also what are some more things to wake this car up? I am not very happy with it's performance....I think my Duramax diesel truck would walk away from this thing in a drag race. Maybe headers, intake manifold, ETC?

I would help to have, a good aluminum dual plane 4bbl hi rise type performance intake {if it's going to be a street car, single plane if a drag car}, a good fuel mechanical or electrical pump & a fuel regulator if over 7psi, 3/8" pickup & 3/8" or #6A/N lines lines & fittings minimum, feeding the pump & carb, quality fuel filter 1 before the pump & 1 before the carb, headers, a free flowing exhaust preferably 2.5" 0r larger {your 2.250" will be OK though add a H or X pipe}, a gauze type air cleaner element like a K&N...  

[MoparMotel]

I'm still learning all this stuff, and will do so for a looooong time to come, but this is definitely the place to gain the knowledge!

I think that apart from the 2 1/2 h pipe some headers would give you some noticable gains.  383's are nothing to compare to modern engines but they are not exactly slow to begin with.  Come to think of it, those diesels do have a boatload of torque your 383 doesn't have.  

What's the rest of your setup?  What year Charger do you have?  What rear end and gears?  I lost a bunch of power going from 3.55 gears to 2.94 with a 440, but it is a lot more enjoyable to drive.

Engine rebuilt 3 years ago. Approximately 1,500 miles on rebuild.

Numbers matching 383 block
bored .30 over with 10:1 pistons-not sure what brand ( had local shop rebuild it )
factory intake and factory hp exhaust manifolds that have been jet hot coated
Edelbrock 750 with manual choke
factory dual snorkel air cleaner
factory rear end with 3.23 gears( no posi, only time I could actually get it to break loose only one tire spun)
factory distributor with pertronix kit
2 1/4 duals with flowmaster 40 series( soon to have H pipe installed )
rebuilt 727 with shift kit

I am going to take it to a friend of mine who works on mopars and have him set carburation and timing. I don't know if its timing or what but this thing has a horrible stumble when accelerating from a stop sign and when you really put your foot in it the car doesn't start pulling hard until after 3,500rpm. When holding the brakes and stepping on the gas the car won't even break the tires loose. Has no bottom end power at all.

[Dino]

That stumble seems to be common with that carb, I've had it happen a few times as well.

After your friend checks timing and a/f ratio go try to break the tire loose again.  From a stand still drop it in first and floor it, no braking or any of that, just gun it.  If your tire doesn't create a wall of smoke something's way off.  I used to do this with my 68 and a 383 all stock except headers.  Tires I had back then were 225 70 14 and it would smoke them (it, open end rear as well).  I am almost positive I had 3.23 gears.

If I do the same now in the 69 with 440 and same size tire with 2.94 open end it'll smoke the tire and stay put while it roasts the poor thing, when I let off a little it moves, floor it again and I can roast it well through 2nd gear.  With 3.55's it was a lot crazier still.   There's a quiet paved road just out of my sub with a really long tire mark, I was shocked when I drove passed it the other day and saw it, so much for quiet road!

When the engine was rebuilt, was it ever dyno'd?  Do you have any numbers off that engine regarding performance?

How's the rest of the car doing?  All brakes work and release as they should?  Suspension is ok?  Just trying to narrow it down here.

[MoparMotel]

Engine was not dyno'd when it was finished. I have not set the timing since I got it back from him, could something have changed since I got it back? The guy who rebuilt the engine is a Chevy guy, and mostly builds chevy engines at his shop, I wonder if he didn't know what he was doing when he did mine or are they not that much different?

He said he had a 69' Roadrunner with a 383 a while back and some friends who have gone to his shop seemed to trust him.

[Dino]

If he's good with Chevy engines I don't see how he would not be just as good with mopars.  If he did an engine rebuild then he should have set timing and a/f ratio.  If all he did was bolt in new parts then there's more work to do.  For all we know your engine is fine but your parking brake is stuck halfway down!

Honestly I don't see anything in your setup that would really hold you back.  There's always better carbs and intakes but stock should work fine.  Have you removed the snorkel to see if it improved? 

Now you did say you don't really care about fuel mileage and just want performance so I say remove the carb, intake manifold and exhaust manifolds, replace with proform or Holley carb with a Weiand, a holley street dominator or Edelbrock performer RPM and add some headers in the mix. 

I'm not all that familiar with cams.  How does it idle?  Nice and smooth or kinda race rough?

[1970Moparmann]

Yes , Check out Proform carbs

I have to second this.   I am VERY impressed with the throttle response of mine.   I'm planning on putting it on my Coronet.

[greenpigs]

If you go the Proform route make sure you get matching pieces if your building one from an existing Holley.

[Cooter]

Yes, Holley Double pumper all the way...

[68blue]

750 Holley DP on my 383 works fine.

Eddy RPM heads and mainfold, TTI pipes, Comp 21-223-4, 3.55 gears

Idle is slightly edgy but drives nice on the street.

[Chryco Psycho]

Engine was not dyno'd when it was finished. I have not set the timing since I got it back from him, could something have changed since I got it back? The guy who rebuilt the engine is a Chevy guy, and mostly builds chevy engines at his shop, I wonder if he didn't know what he was doing when he did mine or are they not that much different?

He said he had a 69' Roadrunner with a 383 a while back and some friends who have gone to his shop seemed to trust him.

A few years back we built a pair of identical engine for two friends trying to outdo each other , I ported the heads on both , tuned both , but one guy took his engine to a ford machinist , his engine made 205 RWHP on a Mustang Dyno , we then took the second car to the dyno with the engine I had fully built & we made an insignificant 50% more power on the same dyno , it made 315 RWHP .
A machinist can make or break the build .

[mopar2]

This is what Ron recommended for mine http://www.summitracing.com/parts/PRO-67213/  can't wait to get it and try it out 

[Budnicks]

Engine was not dyno'd when it was finished. I have not set the timing since I got it back from him, could something have changed since I got it back? The guy who rebuilt the engine is a Chevy guy, and mostly builds chevy engines at his shop, I wonder if he didn't know what he was doing when he did mine or are they not that much different?

He said he had a 69' Roadrunner with a 383 a while back and some friends who have gone to his shop seemed to trust him.

A few years back we built a pair of identical engine for two friends trying to outdo each other , I ported the heads on both , tuned both , but one guy took his engine to a ford machinist , his engine made 205 RWHP on a Mustang Dyno , we then took the second car to the dyno with the engine I had fully built & we made an insignificant 50% more power on the same dyno , it made 315 RWHP .
A machinist can make or break the build .

"I agree 100%"  the assembly is very important or at least as important as the parts selected,  just because some one is a "machinist" doesn't make them a good "engine builder"  , especially when it come to performance applications & techniques... Every style of build, or mnfgr. has their own idiosyncrasies & ways to extract the most power Ford stuff, Chevy stuff, Mopars stuff & others all have their own quirks  ... Always go to someone who is a specialist in the brands you choose to build...

[MoparMotel]

Little update.....

Took the car to a friend yesterday and he put the timing light on it..... Timing was 19 degrees at idle.... got the carb dialed in and timing set at 15... Car runs way better and starts a lot easier. I am going to run this carb for a month or so and see if I like it. The car still has the stumble off of idle leaving a stop sign, and he suggested buying the edelbrock jet kit and going up 2 sizes on the jets and see if this helps the stumble.

If I cannot get this carb dialed in perfect I will probably be ordering the Proform in the summit link above.

[MoparMotel]

Called edlebrock today and explained my motor and stumble and they are sending out new metering rods and lighter springs for free... Pretty good customer service!

One question I was wondering about is this thing has no low end power at all... Won't even break the tires loose with or without the brakes. Does this sound like carburetion or timing or the cam I put in it comp 270/470?

Hoping the metering rods solve the stumble and give me some low end power.

[Cooter]

Called edlebrock today and explained my motor and stumble and they are sending out new metering rods and lighter springs for free... Pretty good customer service!

One question I was wondering about is this thing has no low end power at all... Won't even break the tires loose with or without the brakes. Does this sound like carburetion or timing or the cam I put in it comp 270/470?

Hoping the metering rods solve the stumble and give me some low end power.

Depends on the rearend gear, stall speed of converter(If automatic), etc. as to how much TORQUE you need to "turn the tires over"...Carb tuning will only get you so far if you don't have enough engine. Remember, a 383 Chrysler BIG BLOCK has less stroke than a small block 350 Chevy....

[MoparMotel]

Called edlebrock today and explained my motor and stumble and they are sending out new metering rods and lighter springs for free... Pretty good customer service!

One question I was wondering about is this thing has no low end power at all... Won't even break the tires loose with or without the brakes. Does this sound like carburetion or timing or the cam I put in it comp 270/470?

Hoping the metering rods solve the stumble and give me some low end power.

Depends on the rearend gear, stall speed of converter(If automatic), etc. as to how much TORQUE you need to "turn the tires over"...Carb tuning will only get you so far if you don't have enough engine. Remember, a 383 Chrysler BIG BLOCK has less stroke than a small block 350 Chevy....

Gears- Factory 3.23's. Not sure on the stall, had the transmission rebuilt with a shift kit but not sure if he put a stall in.

[Challenger340]

Engine was not dyno'd when it was finished. I have not set the timing since I got it back from him, could something have changed since I got it back? The guy who rebuilt the engine is a Chevy guy, and mostly builds chevy engines at his shop, I wonder if he didn't know what he was doing when he did mine or are they not that much different?

He said he had a 69' Roadrunner with a 383 a while back and some friends who have gone to his shop seemed to trust him.

A few years back we built a pair of identical engine for two friends trying to outdo each other , I ported the heads on both , tuned both , but one guy took his engine to a ford machinist , his engine made 205 RWHP on a Mustang Dyno , we then took the second car to the dyno with the engine I had fully built & we made an insignificant 50% more power on the same dyno , it made 315 RWHP .
A machinist can make or break the build .

"I agree 100%"  the assembly is very important or at least as important as the parts selected,  just because some one is a "machinist" doesn't make them a good "engine builder"  , especially when it come to performance applications & techniques... Every style of build, or mnfgr. has their own idiosyncrasies & ways to extract the most power Ford stuff, Chevy stuff, Mopars stuff & others all have their own quirks  ... Always go to someone who is a specialist in the brands you choose to build...

Agreed,
being a "Machinist" does NOT neccessarily make one a good "Engine Builder"
however conversely,
IMO,
I have never seen a "GOOD" High Performance Engine Builder, who wasn't fully conversant with Machining, or was more than capable of Machining for themselves if required ?
Sooner later....it boils down to be able to GET, what YOU want, and being able to check it properly requires far more than "plasti-goop" !

Amazing how many supposed wonderful "Engine Builders" I have seen, have NO IDEA "how" to Machine anything.....wouldn't even know HOW to turn the Friggín Machine "ON" if you put them in front of it......yet rely solely on a "machinist" supposedly "doing his job" ?
These type "Engine Builders",
well, IMO.....Even a Blind Chickens gets the "odd" Kernel of Corn ?

IMO,
if you can't TELL the Machinist, HOW you want it done, I guess you are pretty much leaving it to him, and you GET, whatever he KNOWS about Performance Blueprinting ?

Same thing goes for supposedly "magical" Head Porters ?
Unless you are just staying with pretty basic "Pocket Port & Gasket Match" jobs, which really, ANY competent Knumbskull with a Die-Grinder can do......
and you DO NOT HAVE, or HAVE ACCESS TO a Flowbench, or, know how to use one, and READ the Data.....or NEVER DID know how ?
why,
would that someone undertake a "Full" Port Job for an unsuspecting Customer ?

No wars wanted, just stuff to think about....

I got no problem with Guys who want to access GOOD Machining/Blueprinting/Porting, and screw their OWN Engines together, those Guys usually have enough experience, and know enough about their OWN stuff, and smart, and KNOW at least "where" to go to get it.....
Rather,
It's the Guys that really know dunno SQUAT about Machining, or Head Porting, and start Building "Performance" Engines for Customers, then when something goes wrong, wanna BLAME the "Machinist" ?
Why the Machinist ?
THEY are the dimwit that screwed it Together.....did THEY not check it ?

I've seen it all over 35 years....
Guy comes in, giving my Counter Guy "Hell" because his Engine spun a Main ?
Never seen this Guy before in my Life ! Never did any work for him.....
But,
I guess we HAD "Machined" for his "Engine Builder.....
Seems his "Engine Builder", was blaming us ?
Long Story short....
got him to bring it in anyways, FOUND the problem....
seems dimwit put the Main Cap on BACKWARDS !
and,
we gotta listen to THAT ? and the "Stories" floating around for 6 months after.....

That changed our Business protocols....
We ONLY DO "Complete, Done, Assembled & DYNO'd" Engines, NO Exceptions...
or,
Machining Packages, ONLY for people who have come in and "trained" in procedure for 3 weeks in our Shop(usually the lead mechanic at whatever other Shop is using our Machine Pkgs)

[BSB67]

I don't know if anyone is making a 10:1 piston for the 383.  Do a cylinder pressure test, if you have not already.  The 750 DP would work nice IMO.

[71bee]

If you go with a 4150, make sure you take into consideration that you'll have a routing issue with your coil (if located in the stock position). i've helped allotta guys out by using a few brass elbows & 3/8" fuel line to get around this problem. also, some DP's only come with the PVC vacuum nipple in the rear of the carb. if your not worried about looking "stock," the DP will easily outperform an Edelbrock Performer.

[MoparMotel]

Got the new metering rods and springs put in Saturday night. I just took the car for a 50 mile drive about an hour ago, Car now does not stumble anymore and runs great!

[Paul G]

Make sure your throttle cable is adjusted properly.

[MoparMotel]

Make sure your throttle cable is adjusted properly.

What exactly do you mean, as in make sure its tight and there is no play in it? it feels fine and seems to not have any play between the carb and pedal. I know when I put this carb on my kickdown did not work and I had to buy an edelbrock bracket that makes the kickdown work correctly. 

[Paul G]

Have someone sit in the car and push the gas pedal all the way to the floor. You should see the carb open all the way up. If you can open the throttle a little more by hand, adjust the throttle cable till it has the carb fully open. If the cable is not adjusted right it may not be opening the carb all the way. Not getting full throttle.

[MoparMotel]

Have someone sit in the car and push the gas pedal all the way to the floor. You should see the carb open all the way up. If you can open the throttle a little more by hand, adjust the throttle cable till it has the carb fully open. If the cable is not adjusted right it may not be opening the carb all the way. Not getting full throttle.

Ok thank you I'll give that a try.

[71bee]

Got the new metering rods and springs put in Saturday night. I just took the car for a 50 mile drive about an hour ago, Car now does not stumble anymore and runs great!

Just a thought, have you tried the Edelbrock Thunder Seriers carbs? their 800 CFM AVS will really wake your car up. their a better carb than the Performers. 

[MoparMotel]

Got the new metering rods and springs put in Saturday night. I just took the car for a 50 mile drive about an hour ago, Car now does not stumble anymore and runs great!

Just a thought, have you tried the Edelbrock Thunder Seriers carbs? their 800 CFM AVS will really wake your car up. their a better carb than the Performers. 

We put this exact carb on a friends 440 and it ran great. 800 Thunder AVS. I wanted a thunder carb before I got my 750 performer but when I looked at them I noticed they only had a 650 and 800. I figured 650 would be too small and 800 too big.

[71bee]

Nope, that 800 CFM Thunder will work beautifully on your 440. it's just a matter of air/fuel mixture. the re-engineered Eddy AVS carbs work much better & create more power than the AFB (Performer Series) carbs. you can manually adjust the secondary air valve (AVS) to open perfectly to your intake vacuum, thus getting rid of any bogging when mashing the throttle.

[MoparMotel]

Nope, that 800 CFM Thunder will work beautifully on your 440. it's just a matter of air/fuel mixture. the re-engineered Eddy AVS carbs work much better & create more power than the AFB (Performer Series) carbs. you can manually adjust the secondary air valve (AVS) to open perfectly to your intake vacuum, thus getting rid of any bogging when mashing the throttle.

I have a 383 that's mostly stock with around 10:1 compression, a little head work, and a .270/.470 comp cam.

[71bee]

Nope, that 800 CFM Thunder will work beautifully on your 440. it's just a matter of air/fuel mixture. the re-engineered Eddy AVS carbs work much better & create more power than the AFB (Performer Series) carbs. you can manually adjust the secondary air valve (AVS) to open perfectly to your intake vacuum, thus getting rid of any bogging when mashing the throttle.

I have a 383 that's mostly stock with around 10:1 compression, a little head work, and a .270/.470 comp cam.

Okay, then go with the 650 CFM models. I used their 1806 (electric choke) on my 383 & it worked beautifully. if I wasn't trying to keep my Bee looking "bone stock." I would definitely keep that Thunder on my car. the original Carter AVS #6125S that I use is only off by 25 CFM, so i'm not complaining to bad.

[MoparMotel]

This is what Ron recommended for mine http://www.summitracing.com/parts/PRO-67213/  can't wait to get it and try it out 

Now I'm dealing with the hard start issue when warm- probably boiling fuel or some other common edelbrock problem. I am going with this proform that you guys recommended above.

Are there any other parts that I am going to need? I'm using the factory 383hp intake. Will this carb bolt up to my stock intake and also am I going to need any throttle adapters? I know I need to order the dual feed fuel line kit.

Also I'm using a factory style mechanical fuel pump, Will this be ok?

Thanks!

[MoparMotel]

Well I have had enough of this Edelbrock. I had it running pretty good in December but started the car to take it for a ride yesterday and it was idling low and wanted to die at a stop sign or light. It then started stumbling when accelerating. I thought maybe it needed to be cleaned out so I stepped on it and it started hesitating and could barely make it to 4,000-4,500 rpms. Took the car home and put the cover over it.

Time to order the proform carb in the link above and be done with it.

[Budnicks]

Well I have had enough of this Edelbrock. I had it running pretty good in December but started the car to take it for a ride yesterday and it was idling low and wanted to die at a stop sign or light. It then started stumbling when accelerating. I thought maybe it needed to be cleaned out so I stepped on it and it started hesitating and could barely make it to 4,000-4,500 rpms. Took the car home and put the cover over it.

Time to order the proform carb in the link above and be done with it.

Good choice any of the aftermarket Holley type carbs, Proform, Quickfuel {like the 1 pitchered below is $399, with electric choke & vacuum secondaries, at Mancini Racing}, Holley HP & others are all a good choice

[bobs66440]

 

[Cooter]

Quick to go after the Carb, yet no mention of the fuel tank is under it and how clean it is. You say mechanical pump? How many GPH is it? Stock? A Proform carb isn't gonna perform any better if you have other issues that occur BEFORE the carb.

[Mick70RR]

I spent months trying to get rid of that 750 Edelbrock off-idle bog and gave up in the end. I did a lot of reading about the problem and tried every fix recommended but none of them got rid of it completely. I bought a Proform and never looked back, you won't be disappointed.

[Budnicks]

Quick to go after the Carb, yet no mention of the fuel tank is under it and how clean it is. You say mechanical pump? How many GPH is it? Stock? A Proform carb isn't gonna perform any better if you have other issues that occur BEFORE the carb.

That's pretty much why, I recommended too put a cleanable fuel filter before the fuel pump & before the carb so he could see if there is any crap going thru the system... We kind of have to go on the assumption, he's all ready eliminating crap in the system, bad fuel, bad pick up or bad tank etc... The post could be 2 pages long otherwise...

[MoparMotel]

I spent months trying to get rid of that 750 Edelbrock off-idle bog and gave up in the end. I did a lot of reading about the problem and tried every fix recommended but none of them got rid of it completely. I bought a Proform and never looked back, you won't be disappointed.

^This is where I am at. I tried the fixes, different metering rods/springs, changes in accelerator pump, ETC. Helped but bog is still there.

The reason I think it is the carb is because I had the factory carter 625 that was rebuilt on this motor for the first year, and the car ran great I just swapped the 750 on there to hopefully get a little more top end power out of it. It ran and started fine with the factory carter, these problems started when I put the eddy 750 on.

[Dino]

I spent months trying to get rid of that 750 Edelbrock off-idle bog and gave up in the end. I did a lot of reading about the problem and tried every fix recommended but none of them got rid of it completely. I bought a Proform and never looked back, you won't be disappointed.

^This is where I am at. I tried the fixes, different metering rods/springs, changes in accelerator pump, ETC. Helped but bog is still there.

The reason I think it is the carb is because I had the factory carter 625 that was rebuilt on this motor for the first year, and the car ran great I just swapped the 750 on there to hopefully get a little more top end power out of it. It ran and started fine with the factory carter, these problems started when I put the eddy 750 on.

It's the carb, I have the same issue, although not as bad as you guys it seems.

I'm swapping it for a tq this spring.

[MoparMotel]

I found this holley 750 double pumper on craigslist right by me for $150. Thinking about giving this a shot just for the price. If it doesn't work correctly I can always throw a rebuild kit in it or save it as a spare.

[MoparMotel]

If i'm running an edelbrock right now what all will I need to make the swap? That carb already has the duel inlet fuel line as pictured, will I need any other parts to swap the carbs out such as kickdown linkage brackets or anything? I have no idea how to tune a Holley carb so I am going to have a friend who has experience tuning them tune it for me.

[MoparMotel]

Did some research on Holley's Technical Department and they recommended a 670 or 770 street avenger vacuum secondaries for my car. Now for the decision making, go with this 750dp and at least try it, or just save my money and go with the proform or quickfuel that were recommended on here. Hell, maybe try both 

[terrible one]

If it were me, considering the price of the new Proform unit, I'd go with the double pumper off of Craigslist. As long as you know your way around them (or have a book on them) you can't really go wrong. Lots of happy 750 DP users here.

[Chryco Psycho]

you need the 20-7 throttle linkage adapter & a fuel line for the Holley

[MoparMotel]

you need the 20-7 throttle linkage adapter & a fuel line for the Holley

Thank you I'll look into ordering one in the morning

[MoparMotel]

Sorry if I am dragging this on, just trying to learn as much as I can.

the 750DP that I posted above has been sold. After going to a few shops near me I have three carbs that are available. If possible I would appreciate some input on which of the three would be the best and also which one you would chose.
1. Holley 80508S =  #4160 carb 750 vac. secondaries electric choke- $320
2. Holley 670 street avenger- $399
3. Holley 770 Street avenger- $399

Is one of the street avengers worth the $80 over the 4160? If it is would you go with the 670 or 770 on a mild 383 with a cam and stock everything else?

Also this is a picture of my current set up- The metal fuel line was purchased from year one, I'm guessing this can't be used and I am going to have to find a different line from the pump? I'm already planning on getting the dual feed line and 20-7 adapter as Chryco advised above.






Thank you I appreciate the input!

[terrible one]

FWIW, I'm running a 750 VS on my mild 383 and it's great. No hesitation off the line. Here's a vid in action   : http://www.youtube.com/watch?v=BAWpWcgqX6w . Knowing that and it being the cheapest, that's what I would go for but that's just me.

If you don't have any other plans for the Year One line, I would simply make use of it as much as possible, cut it near the valve cover where it comes up so that you will only have to use a couple inches of rubber line to connect it to the Holley dual feed line.  

[MoparMotel]

FWIW, I'm running a 750 VS on my mild 383 and it's great. No hesitation off the line. Here's a vid in action   : http://www.youtube.com/watch?v=BAWpWcgqX6w . Knowing that and it being the cheapest, that's what I would go for but that's just me.

If you don't have any other plans for the Year One line, I would simply make use of it as much as possible, cut it near the valve cover where it comes up so that you will only have to use a couple inches of rubber line to connect it to the Holley dual feed line.  

That's the 4160 on your car? Very impressive video! My car has no where near the throttle response yours does in the video. If that's the case I'd be more than happy with the 4160 for $320

[terrible one]

FWIW, I'm running a 750 VS on my mild 383 and it's great. No hesitation off the line. Here's a vid in action   : http://www.youtube.com/watch?v=BAWpWcgqX6w . Knowing that and it being the cheapest, that's what I would go for but that's just me.

If you don't have any other plans for the Year One line, I would simply make use of it as much as possible, cut it near the valve cover where it comes up so that you will only have to use a couple inches of rubber line to connect it to the Holley dual feed line.  

That's the 4160 on your car? Very impressive video! My car has no where near the throttle response yours does in the video. If that's the case I'd be more than happy with the 4160 for $320

Sure is! And thank you.

The carb is actually an older model, no idea for sure because the choke horn has been milled off:

[MoparMotel]

FWIW, I'm running a 750 VS on my mild 383 and it's great. No hesitation off the line. Here's a vid in action   : http://www.youtube.com/watch?v=BAWpWcgqX6w . Knowing that and it being the cheapest, that's what I would go for but that's just me.

If you don't have any other plans for the Year One line, I would simply make use of it as much as possible, cut it near the valve cover where it comes up so that you will only have to use a couple inches of rubber line to connect it to the Holley dual feed line.  

That's the 4160 on your car? Very impressive video! My car has no where near the throttle response yours does in the video. If that's the case I'd be more than happy with the 4160 for $320

Sure is! And thank you.

The carb is actually an older model, no idea for sure because the choke horn has been milled off:

Trying to look at the photo and see how your kick down is set up... did you put a cable operated set up on? I've got the factory metal bar setup

[terrible one]

FWIW, I'm running a 750 VS on my mild 383 and it's great. No hesitation off the line. Here's a vid in action   : http://www.youtube.com/watch?v=BAWpWcgqX6w . Knowing that and it being the cheapest, that's what I would go for but that's just me.

If you don't have any other plans for the Year One line, I would simply make use of it as much as possible, cut it near the valve cover where it comes up so that you will only have to use a couple inches of rubber line to connect it to the Holley dual feed line.  

That's the 4160 on your car? Very impressive video! My car has no where near the throttle response yours does in the video. If that's the case I'd be more than happy with the 4160 for $320

Sure is! And thank you.

The carb is actually an older model, no idea for sure because the choke horn has been milled off:

Trying to look at the photo and see how your kick down is set up... did you put a cable operated set up on? I've got the factory metal bar setup

Yes, I went with the BPE cable operated setup because I started with nothing and those factory kickdown setups are expensive!

[MoparMotel]

FWIW, I'm running a 750 VS on my mild 383 and it's great. No hesitation off the line. Here's a vid in action   : http://www.youtube.com/watch?v=BAWpWcgqX6w . Knowing that and it being the cheapest, that's what I would go for but that's just me.

If you don't have any other plans for the Year One line, I would simply make use of it as much as possible, cut it near the valve cover where it comes up so that you will only have to use a couple inches of rubber line to connect it to the Holley dual feed line.  

That's the 4160 on your car? Very impressive video! My car has no where near the throttle response yours does in the video. If that's the case I'd be more than happy with the 4160 for $320

Sure is! And thank you.

The carb is actually an older model, no idea for sure because the choke horn has been milled off:

Trying to look at the photo and see how your kick down is set up... did you put a cable operated set up on? I've got the factory metal bar setup

Yes, I went with the BPE cable operated setup because I started with nothing and those factory kickdown setups are expensive!

Thanks, I'll check into one of those or see if there is a way to use the factory set up.

[MoparMotel]

Alright guys, I really appreciate the help but have one last question. After much research I decided to go with the 770 Holley Street Avenger.


I went to call and order the carb today and second guessed myself when the holley tech on the phone said that I should be going with the 670 instead of the 770.

I told him 383 big block and the spec sheet for my Comp Cam said the range was 1800-5500rpm and he said the 670 would be a better fit.

Now the question of the hour.... 670 or 770?

[404NOTFOUND]

I took the crappy Edelbrock off my 440 and put a Holley Street Avenger 770 on it. I'm really happy with it. That is on a stockish  engine with too big a cam, Mopar Purple 509 lift, 292 duration. I've made lots of changes since and the throttle response keeps getting better. I tried an 850 double pumper that I had on hand and as expected, it was too much. I bet a 750 dp would be great but, half the people say yes and half say no. A Street Avenger is a very safe route to go.

[MoparMotel]

I took the crappy Edelbrock off my 440 and put a Holley Street Avenger 770 on it. I'm really happy with it. That is on a stockish  engine with too big a cam, Mopar Purple 509 lift, 292 duration. I've made lots of changes since and the throttle response keeps getting better. I tried an 850 double pumper that I had on hand and as expected, it was too much. I bet a 750 dp would be great but, half the people say yes and half say no. A Street Avenger is a very safe route to go.

Good info... If you have a 440 with a .509 cam and run a 770 then my 383 with a .470 cam out to be just right with a 670

[404NOTFOUND]

I took the crappy Edelbrock off my 440 and put a Holley Street Avenger 770 on it. I'm really happy with it. That is on a stockish  engine with too big a cam, Mopar Purple 509 lift, 292 duration. I've made lots of changes since and the throttle response keeps getting better. I tried an 850 double pumper that I had on hand and as expected, it was too much. I bet a 750 dp would be great but, half the people say yes and half say no. A Street Avenger is a very safe route to go.

Good info... If you have a 440 with a .509 cam and run a 770 then my 383 with a .470 cam out to be just right with a 670

Yup,  I'm kinda thinking that. We all want the biggest carb possible and you might gain a bit more power with a 770 but, if it's too big, the bogging will get old real fast. With the 670, you already know it will work perfectly.

[MoparMotel]

Man, I just called the performance shop in town that is going to install and dyno tune the car with the new carb and he said "no don't get the 670 get the 770 it's a big block you can run the 770"

[Dino]

Man, I just called the performance shop in town that is going to install and dyno tune the car with the new carb and he said "no don't get the 670 get the 770 it's a big block you can run the 770"

You can run either but I'd go with the 670.

[charger_fan_4ever]

Edelbrock makes a good plow truck carb ;-)

Seat of the pants meter/wallet meter grab a 650 DP and buy a proform main body and voila you have a 750 4150 carb on the cheap. Make sure the throttle shafts are not all loose, or it will run like crap. Put a straight edge on the baseplate to make sure it hasn't been over tightened and warped. The holley 650,700,750 all use the same baseplate, so adding a proform mainbody makes it a 750.

Or if you can find a 700 or 750 4150 cheap just mill the choke tower off and go have fun.

In my small block mustang days I tried a 750 Holley 4160 vacuum secondary and replaced it with a 750 DP. Miles difference on a 425 Hp small block.