Not exactly sure of the tranny gears. I just told the guy to build me a V8 camaro T5 tranny with an S-10 tailshaft and a mechanical speedo. The rear end I'm running is a 3.73 from a 65 truck. It happened to be the right width @ 62" from wheel back to wheel back. I recently drove from Denver to Kansas City (1200 miles round trip). I averaged about 18 mpg @ 70mph & 2000 rpm. Ran like a dream. Just a little bouncy with the monoleaf front springs. I think I need a set of shocks that match the springs. wink