I'm picking up a set of 452 head castings that the current owner had tuned up with a cleanup decking, 2.15/1.81 intake/exhaust valves with a 3-angle job, new guides etc. but no port work. My current 346 heads are pretty tired (pitted seats, loose guides etc.) so when these popped up for cheap I snagged them.
My question is, is it worth porting these to make better use of the bigger valves or will I not see enough gains on the street to justify the time or cost. I've never ported before but I'd consider doing a basic job myself. I imagine to have a shop do even a basic 'cleanup' or pocket port and gasket match would be pretty expensive even if the rest of the work has been done.
Current engine combo is a very mild 1971 440:
Stock pistons, rods, crank etc.
Melling MTD2 'rv' cam
Exhaust duration @0.050: 214
Exhaust lift: .443in
Intake duration @0.050: 204
Intake lift: .421in
Edelbrock CH4B intake
Holley 750 vacuum secondary
1-3/4" primary headers
The main reason I picked up these heads is because they were just 'gone through' and are cheap. The bigger valves were just gravy assuming I don't actually lose performance due to a drop in velocity. Thoughts? Thanks!
If you have the tools to disassemble the heads, then I would go for it. Even just some light bowl blending and casting clean up would compliment the bigger valves !
Agreed. Don't pay somebody else to do it. But if you want to do it yourself, those heads sound like a good case for it. The lowest-hanging fruit is opening up a set of stock castings.
Working on iron heads is slow & tedious, though. Don't get too ambitious & perfectionist on the first cylinder - you gotta repeat that job 7 more times.