well it seems like the cobra heads are too difficult to put on but what about the regular gt heads? i have a 98 so i dont have the pi heads so i would think the gt heads would give me lots more power and higher in the power band because of the larger cam lobes...any advice on whether or not this is possible would be appreciated.

 

you mean gt heads AND cam, right?

 

The way I understand it, the heads are identical except for the cams. The PI heads for the mustang GT has a different cam profile then the one for the F150. HP and torque come in at a much higher rpm. Good for light cars but not for heavy trucks. Get the GT heads and switch out the cams from the F150...

 

It is my understanding that all 5.4 and 4.6 heads and cams are the same if they are the PI (Performance Improved) versions. It is my understanding that trucks and Mustangs converted in 1999 to PI and Crown Vics and GMs converted in 2001 to PI heads and cams.

When the Fords got PI heads and cams--the intake manifolds also changed. The changes involved in the PI 4.6 engine was the reason that the 98 GT had 225 horsepower and the 99+ GT Mustangs have 260 horsepower.

The difference in Horsepower and torque peaks between the trucks and the Mustangs are due to computer ,throttle body size,and exhaust system (dual exhaust, and four cats on GTs).

 

The Cam profile on the PI heads for trucks is different from the non PI heads for the trucks. I am not sure about the cam profile on the Mustang compaired to the truck profile.

Regards

Jean Marc Chartier