Exhaust port height comparison
 

Does anyone know if the exhaust port height on the ZZ 454 is higher than the steel heads on a stock 69 396 / 325? I am comparing my ZZ heads to some heads that were on the mystery motor that was in my car when i bought it. The block checks out to be a 1977 454 2 bolt, i have not been able to ID the heads.
Thanks,
David

Re: Exhaust port height comparison
 

I replaced my 1972 402 with a ZZ454 about 10 years ago and while I did not measure the two to verify I believe there were no differences in height. Only issue I had was the threads on the drivers side head A/C bracket mounting were one size too large, so I could not use the factory bolt and there were no provisions for the factory starter brace. All in all no big deal for the overall ease of the swap and improvement in performance.

Jake