what trans to use for road race?

Manual trans with a close ratio gearset.

I was talking to Tim Herren a couple night ago that vintage races a clone 70 AAR and has put on track rental days for years at Willow Spring Raceway. He said the Tremec 5 speed conversions are a wider a spread than optimal. He's driven Mopars, Mustangs, Camaros, etc with those Tremec trans and was not impressed. He thought they were great transmissions for cruising around and dual purpose. And you can take one to the track and have a great time and all. But just not the optimal gear spread for road racing.

The close ratio gearset is 2.44 1.77 1.34 1.00 or 2.47 1.77 1.34 1.00. Most all 71-74 are this close ratio. And 1970 T/A and AAR with 4spd are close ratio.

http://www.allpar.com/mopar/transmissions/four-speed-manual.html