so i am a mechanic who just recently bought a 1996 gt. my first modular, i am very familiar with alot of the mods and updates and have owned man other mustangs, but to the point i got a great deal from a friend at ford and through my shop on a 2003 mustang pi factory shortblock, so my question is........what is the differance between the pi heads and nonpi heads, and i dont care about cams and springs thats all going to be bad ass, so is it just porting or is the cc's of each cylinder differant, if so i plan on just porting my 2v heads when i pull them off or getting a set of stock 2v nonpi heads an having the done. so if anyone knows or has a website i can read let me know. thanks