Welcome to gpf, to help us help you, how many miles? What shape is the car is? As slowpoke said you make the call..Personally I would top swap the car. If your looking for more power all that info can be found here http://www.grandprixforums.net/top-s...info-7763.html as for the newer gtps are supercharged six cylinders, and the gxps are eight cylinders, but the aftermarket is awful slim on the gxps imo. But anyway, good luck and have fun