kkinsman

HOW MUCH HORSEPOWER WILL A SET OF GT40P HEADS AD

TAPOUT

Depends on what you're replacing with them. What else do you have done? If you are only changing the heads, a little hp. If you are installing a new cam while it is apart, and better valve springs, and a new intake, and bigger TB, larger injectors, etc, it will net more power because everything has to work together.

chath_brick

this is a great article on the gt-40p head:

http://www.stangpro.com/html/article...les/gt40p1.htm

keep in mind you need special headers if you get some

danltr450

just a little fyi i am running gt40p heads and i plan to use bbk long tubes. before i had purchased the 351w swap headers i mocked them up on the heads to see if there would be clearance, only 1 cylinder had a plug close that would require a 90 degree boot. just a fyi

94 G STANG

i installed my gt40p's with bbk unequal length and they fit
i used 90 degree cables though