5 speed interchange

I have a 350 in my car with a Borg Warner T-10 behind it. It has a blowproof bellhousing with a hydraulic clutch set-up. I would like to install a 5-speed to get the O/D. Does anybody know which trans might bolt up to this bellhousing and be able to about 400-450 hp?

Thanks in advance.

You have two choices that come to mind right off hand .

One would be a built T5 using Astro Performance A5 gears and the other would be a Tremec 600 (chevy version) .

Both are expensive but both should bolt up to your bellhousing . Your other option is a T56 unit with an adapter to bolt up to the bell housing as well .