Hey folks, I just bought a 04 BA XR6T about a month ago off my neighbor, when I bought it it was making 440rwhp running 3" turbo back exhaust with a 5" cat. I recently bought an x-force stainless steel turbo back exhaust with the 4" dump, 3 and 1/2" cat back (ill be running the cat I already have and not using the x-force cat) and was told once its been fitted, the 4spd auto wont be lasting very long. Which brings me to the question I should've asked at the start lol, can anyone recommend a good gearbox that will withstand the extra hp and roughly what will it cost? Ive heard 2 speed powerglides as a recommendation before but I also want to drive around town and 2speeds will be quite uncomfortable. Any info is welcome I'm all ears, Thanks