PI verses non PI exhaust manifolds

[Big Show 96]

Does anyone know if there is any difference between the 96-98 ex manifolds & 99-04 ones. I know the studs are different sizes. Any hp difference??



1996 gt

BBK CAI
BBK 75 mm TB
BBk O/R H-PIPE
40 series flows
steeda UDP
Ford racing Alumn Drv Shaft
Ford racing C-springs
01 long block
3:27 5spd

 

[hollywoodstang]

I Have PI heads done and the old headers bolted right up. I think it's the exact same thing

 

[CobraRed_96_GT]

Same bits

 

[Big Show 96]

When I swapped from the 96 engine to 01 I reused the 96 manifolds & it all bolted up perfect. Just heard a few rumors that they may be different flow wise. I plan on changing them out soon anyway for some Lt's. Thanks for the reply!!