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

I thought BTRs could be rebuilt to take decent power like yours? That way you retain all 4 speeds!

^whs, right build and right tune and you should be able to retain the Btr.

Plenty of built BTR,s running more grunt then that. Id rebuild that box and retain the drivability of your car.

Which would lead OP to the next question, what's a BTR rebuild worth for 450hp at the rears? Two grand? Just guessing.

Mine was around that about 8 years ago and held up well for the 3 years I had it.. That was with a reworked converter to 3000rpm.

Alright thanks for the info guys, going by what everyones saying the BTR should be ok if I can find someone to build it properly, can anyone recommend a good transmission workshop in the south east QLD area?

Mine was around that about 8 years ago and held up well for the 3 years I had it.. That was with a reworked converter to 3000rpm.

Hey mate wat power were u making when u had that gearbox and who built it for you?

Close to 450hp but other cars from the same workshop were running over 500hp. I dont know who built the box as the work shop contracted that out to a transmission builder at the time but the BTR has been out for years, so plenty of places can toughen them up.

Try checking out some other threads. There will be some info in there. I wouldnt put a 2 speed glide in at that power output but you could investagate a C4 transplant but probably will cost just as much as building your BTR.

Alright mate thanks for the help