I have a few questions for you guys...

1. (I have been fighting with my friend on this) On our GPs ,on the shifter you have 1 2 3 then D can I use it like a manual? Like 1st then shift to 2nd then 3rd then D? If yes do I have to take my foot off the gas to switch from gear to gear?

2. Can I add performance shifting to my 97 GT if I dont have it?

3. What are the gains from performance shifting & would i want it?

Thanks

i hav been contemplating the exact same things for like a month and would also like to know. About the performance shifting, is it controlled by the ecu? if so all you would hav to do is reprogram it, right?

You can manually shift without taking your foot off the throttle.
1-2 will automatically shift whether you like it or not at the rev limiter.
2-3 and 3-4 you will hit the rev limiter and it will not shift until you manually shift.
If you have a stock PCM you may gain a bit by manually shifting only because the stock PCM may shift sooner than optimal, especially 2-3, and 3-4.
You can gain the benefits of performance shift with a reprogrammed PCM, or a tuner. Nowadays, the only benefit of having perf. shift is the fact that you can have 2 different programs in your PCM and switch back and forth with the PS button.

With any DHP pcm you can add performance shift by grounding pin 21 on the pcm harness.
You can also enable this feature with a tuner like crimpton said, but you can also just edit the tables in such a way that when you far into the throttle it'll automatically get very firm.