My Son has a '97 V6(my old one) and he ended up going with duals because it helped with the HP gain. I really don't think you'll pick up any HP until you go to dual exhaust. You can purchase one without all the big sound and still get off the line quicker. I'm not sure about the stock diameter, but he went with 2.25". He had the shop cut right after the cats, and go true dual out the back-big difference. Not alot of money invested. The '95 GT tailpipes were used for both bend and axle clearance. Do you have a K&N filter in it? Even a drop in would be better than the stocky.