I have a used Pypes Off-Road X-Pipe for a '99-'04 V6. $100 OBO. Due to shipping costs this is available for pick up only. (Will fit stock manifolds as well as shorty headers.) Thank you.
The y-pipe is actually 2.5" regardless of model, but they do make them separately for the V6 and the GT. In the pictures, the only difference between the two is that the one for the V6 has holes for 2 sensors, where the one for the GT has holes for 4 sensors, which as you can see in the picture mine has holes for 4 sensors as well so I honestly don't see why it wouldn't fit.