Never heard of the "5.4" PI head swap, its just "A" PI head swap. PI mustangs are 99-04, the truck, where you will find most 5.4's got the PI heads in 2001.
But either way the are the same PI heads/cams. There is a website somewhere that has all the info. I looked but didnt find it, but I did find another good one.....
thats exactly what I was hoping to hear. to know that the set of sohc heads from a 03 5.4 that I have are the same heads that I was going to buy for my 96 GT. now I just gotta figure out a decent cam that I can run when I do the PI headswap