Originally Posted by Gtxxjon
Hi Folks, the replies are getting more wacky by the day, but its still a good thread!

I only got interested because its the COMBO that I want to run!
1971 sixpack 'all-iron' engine with a sixpack, exhausting through them AWFUL HP manifolds... blah

So will someone out there PLEASE tell me the BEST COMBO???

Basically what I'm saying, who's got the best 'ALL-IRON' set-up, WITH HP manifolds and what's the CAMSHAFT choice...???

Obviously the 'supposed' SIXPACK naughty Nick was running, was a POO motor with low comp pistons, 516 heads (probably) and a lumpy 'OLD SCHOOL' cam... fan


Just like any other motor. Maximize cylinder pressure for the heads and gas you have available, good heads, good exhaust, the right type of cam.

Any number of part combinations can get you there. The difference between the 450 HP and 475 HP engine with the things I mentioned above is going to be in the tune and tweaking the details.

Assuming std stroke.
915, or 906, or 452 Head? It does not matter. Any of them can flow 270 cfm. Match it up with the right piston. I'm not a reverse dome piston fan. I use the 915, with a dish. So much cleaner. 915 availability and cost to make them right might be higher than the others.

Solid lifter, fast rate cam and decent rocker set up. Wide lsa, probably would not go over 240°@0.050 on the intake.

2 1/2" mandrel bent exhaust with a straight through muffler.

Full street trim should run 12.50s @ 112 mph in full weight B body. Add tires, gear, and converter, 12.00.