How much modification its not a one piece it comes apart in 3 pieces
It depends on what kind of exhaust you're running. Even if you're running takeoff GT duals, you'd need to do some modification to get it to fit. What it comes down to is that if you're going for dual exhaust on a v6 anyway, might as well just fabricate (or have the shop fabricate) your own H-pipe.
Also, an H-pipe is unnecessary on the 3.8. Since the 3.8 has an even firing order, there is no need for a crossover to equalize pressure. I know it says that I have a custom H-pipe in my sig, but I did that before I realized it was unnecessary