need some pi head info

[camarohunter]

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

 

[CobraRed_96_GT]

Generally NPI heads flow 150/150 and PI's flow 165/150, but:

Non-PI and PI Heads

Lift in Inches – Non-PI (’96-‘98) – PI (’99-’04)

.100 – 046 - 054
.200 – 067 - 078
.250 – 086 - 098
.300 – 104 - 119
.350 – 135 - 145
.400 – 147 - 156
.450 – 159 - 161
.500 – 170 - 166
.550 – 176 – 168

Non-PI ('96-'98) Heads have 146cc runner volume for the intake ports and 1.75"/1.34" (44.5 mm/34 mm) valves.
PI ('99-'04) Heads have 159cc runner volume for the intake ports and 1.75"/1.42" (44.5 mm/36 mm) valves.

Ported Non-PI and PI Heads

Lift in Inches – Non-PI (’96-‘98) – PI (’99-’04)

.100 – 061 – 060
.150 – 089 - 086
.200 – 112 - 116
.250 – 131 - 141
.300 – 146 - 160
.350 – 160 - 169
.400 – 173 - 176
.450 – 185 - 182
.500 – 188 - 185
.550 – 193 - 186

NPI heads: 52cc combustion chamber

PI heads: 44cc combustion chamber