I run a Tremtec on a '70 Challenger behind a 496. It was an auto to manual conversion. Originally a 318/904 car. Fit was as advertised. I had to add the normal manual transmission hump plus an additional piece supplied by Keisler to increase clearance in the bell area. Apparently 70's built in California are the tightest in the bell area and that's what I have. I had plenty of clearance to shim up the transmission mount to dial in drive line angles with the OE axle housing and perches.

Mine is the 600 ft lb rated unit with .82 (road race) OD. First gear is higher (lower numerical) compared to the 500 ft lb version and works great. Its just low enough for smooth starts and low speed maneuvering. Even with fairly sticky street tires, nailing it in first would just blow off the tires. 1'st is just a good get her rolling gear in my application. If I wind it up I can feel some shifting resistance in 3'rd gear but with a stroker that doesn't need to run over 6,000 RPM its not a problem. With a faster spinning engine I can see how it might be.

Mine is an earlier version transmission (about 8 YO). I did upgrade the shifter to the newer version and that helped a lot.

I love the transmission and enjoy driving it. Getting 14 MPG in a fairly hot cammed 496 on road trips isn't bad either.