w8less

for once i agree with adder? did you read what he just typed out??

oh yea way to go adder you werent even mean to the noob

AdderMk2

Do I get a cookie?

StalkerGT

hey im fairly new to the mustang world and dont know much about heads....on here to try to learn a few things...didnt really understand the whole thing about compression and combustion chambers, especially the difference in gt-40 heads

AdderMk2

If you dont understand things... research. Google stuff, read read read... If you are confused on something, ask. If you have a problem that you cant figure out... ask

but dont come in here and ask what the differences are, because if you had searched, you would have found your answer.

FoxGT

Agree with all of the above. Not sure if it helps or not, but I've been running an x303 with the GT40Ps with 1.6's am no where close to hitting with stock pistons. I run 14* btdc base on 89 octane with no issues.

nitrous_bob

1) dont bother
2) if u did...pretend you still have E7's

jojobanks

don't the gt40p heads have a different spark plug angle as well? They require different headers?