Or, keep it simple, and put a Lambo engine in the GP? = Lambo fast GP.

Basically with the 3100 you have a turd. Yes it will drive, and will continue to drive, but that's about it.

Sell it. Buy a GT and turbo it. Source your own parts, read everything you can, and you'll save money.

IF you don't want to stay with a W-body, then get an LS1 powered car. They are fairly cheap, plenty of power, and easily modded.