TrimDrip

I would think someone would be able to run more compression or timing with a procomp over a gt 40 head, seeing how it is aluminum.

FivePointOhh

would you like to elaborate on your theory?

ctgreddy

i think he means due to the cc of the head it would bump up compression a bit. or it could atleast. but being aluminum has nothing to do with it.

TrimDrip

Aluminum dissipates heat quicker than iron allowing more compression or timing to be ran due to less heat in the chamber.

FivePointOhh

after having the gt40's milled on the deck like they should be before being installed the cc volume will be almost the same ~60cc

they are the same.

but you caught on to what i was getting at aluminum means nothing, thats why i didnt highlight it.

TrimDrip

A motor that is optimal at 9:0:1 compression with iron heads would be optimal at 9:5:1 (or so) with aluminum heads.

FivePointOhh

you are gonna have to explain that one, that makes no sense. why wouldnt an iron head be optimal at 9.5:1? so you're saying with my iron heads with 52cc chambers with approx 10-10.5:1 compression i wont gain anything out of it cause its not within your specified optimal range??

TrimDrip

I bought a set of 190cc procomp heads about a year ago and never ran them. The biggest difference is the exhaust port. the exhaust ports look like they are twice the size of the stock ford heads. Honestly, i don't know if a 1-5/8s header flange will fit them. It would take a motor that needs a lot of exhaust flow to make good power with them. I wouldn't try them on a 302. 302s just don't need that much flow. If they were going on a 347, they would do better than the gt-40s.

FivePointOhh

that response in no way addressed compression.

FivePointOhh

yea because you aren't allowed to port your heads or anything