2002 Pontiac grand Prix gtp supercharged

The GTP take a heavy duty transmission, identified by the "HD" at the end of the model number. The transmission from a '98 is likely the same but probably won't interchange because of changes in the electronics over the years. Some Google searching or some advice from a transmission shop or possibly an auto wrecker will be needed to make sure you have the right one. Changing them is a lot of work and if the electronics aren't compatible it won't work and you'll end up doing it twice. Don't try to make something fit that isn't a guaranteed plug and play match.

Notice I may have misread your question. The same applies if you're wanting to put the engine from one year to another. In this case it is highly unlikely the electronics will match. You would need to change the wiring harness, computer etc. etc. to make it all work. Not worth it, especially if this car is your daily transportation.