Ok, enough of the fvckery. I don't usually take Wiki's word for it, but here, click the link and scroll down to the 7th gen cars and take a look at the engines available. There is NO reason why this motor will not work in your car. Heck, I could put it in my 00 GT if I wanted to. In fact I'll be likely installing an 07 Buick Lucerne motor in the near future. Just using my wiring harness and whatnot.

Pontiac Grand Prix - Wikipedia