Hey, looking for a numerically lower than 2.76 8 3/4 gearset. I was told MOPAR made something in the 2.40 range at some point. Anybody have a line on a set? I have a 9" with 2.47s, but would sure like to keep it MOPAR.
I'm planning to be at Speed Week in August to break the Classic Production A engine Record.
Thanks
I own the famous "Lindsley's Plymouth" that was run at Bonneville. The rear they used was a Gm rear with 245:1 gears. Had funky Toronado or Riviera wheels on it. WINGNUT
mopar did make 2:45 gears for the 8-1/4 though ,
have heard & have read at least one old magazine article of a lower rear gear for the 8-3/4 , think it was 2:50 , never said if it was aftermarket or specially made , also no pictures , it was just a text article .. old mag , may of been a typo
Quote from: Lifsgrt on May 27, 2020, 02:45:41 PM
Hey, looking for a numerically lower than 2.76 8 3/4 gearset. I was told MOPAR made something in the 2.40 range at some point. Anybody have a line on a set? I have a 9" with 2.47s, but would sure like to keep it MOPAR.
I'm planning to be at Speed Week in August to break the Classic Production A engine Record.
Thanks
sounds like an awesome project , would love to hear / see more about it sometime :cheers:
Well now you done it...we want pics!!! :2thumbs:
This guy seems to know his stuff and cites these ratios for the 8 3/4" axle.
Quote2.76, 2.93, 3.23, 3.31, 3.55, 3.73, 3.91, 4.10, 4.56, 4.89, 5.17, 5.57
http://www.crazysmopar.com/tech_rearax.html
IIRC there's nothing taller than 2.76 for the 8.75 rearend. Lack of clearance for the pinion in the case.
Mopar built taller-geared cars in the smog era but I think those were all 8.25 and 9.25 rearends.
:Twocents:
You might wanna consider using a Ford 8.8 instead of a Ford 9. Higher pinion design = less parasitic drag and less gear heat. Ford made a 2.47 (and a 2.73) gear for it and the aftermarket is pretty supportive.
Thanks for the help