just bought a bbk 75mm throttle body and c&l plenum. the plenum is ported, does porting make that much of a difference?

 

You might notice a little difference with a good porting job. Alot of peeps say wait on plenums and TB's until the end of your mods. When I had my nitrous motor in my '01 GT, I noticed a nice gain N/A with the addition of a C&L plenum and BBK 75mm TB. I think you made a good choice.