[blykins]

I'm not a T-56 fan and never really have been. They are longer than a TKO, bigger around, and heavier. I have also never really seen a situation where you need two overdrives.

For a SBF making 425-450 hp, the torque will be down around 375-400 lb-ft. You have lots of options there: a TKO 600, a worked T5, or a Toploader.

The T5 and the Toploader are the best shifting transmissions out there, bar none. The TKOs are a little notchy, but better when they break in, and are even better when they are modified internally.

For a peakier engine, (read shifting over 6000 rpm), I would recommend the internally modified TKO 600 if you go that route.

Depending on the rear gear ratio and where you plan on driving the car the most, a Toploader makes a VERY nice drivetrain complement, and if you go with the factory 289 block/factory heads, the drivetrain would all look period correct.

I have seen more and more guys opting for completely period correct builds, especially in the nice cars like the ERAs, Kirkhams, etc.