I used to have a T56 in the goat, but it broke and I replaced it with a TH400. I'm contemplating putting a stick back in since I still have my clutch pedal in the car and the slave cylinder is still there. I even thought about an old Muncie 4 speed, but I still wouldn't have overdrive. What's my best option?

 

A modified T56 Magnum at the very least. You are really getting into race transmission territory at those levels though. Something like a Liberty or G Force race trans is ideal but don't come with over drives.

 

http://rpmtransmissions.com/index.html

 

I think the shear weight of the GTO combined with that much power is asking a lot from a typical manual. As mentioned, a G-force or Liberty would handle the task. For an overdrive, if you have the funds, a Gear Vendors OD could be adapted to the back of just about any transmission on the planet and they're very stout.

Mike

 

Not a Tick

But after reading some of RPM's post I am sure they can steer ya right. I mean their trans is in the pig of a camaro that lingenfelter has flying.

 

As others have mentioned, 1200rwhp is a huge amount of power to expect any synchronized manual transmission to withstand for a long period of time. That said, our Level 4 with Cryogenic Treatment and REM Polishing would be our best option, and we could get it shipped to you for less than $5000: https://ls1tech.com/forums/manual-tr...-body-gto.html