Low compression "build" and cruise rpm?

3.23 gear and 11" converter with a big auxiliary trans cooler for extended highway.28" tall tire (275/60r15). Shumacher headers fit great and run 2.5 exhaust. Any 750cfm carb that you like.

Max cruise rpm is whatever you can stand. 3500rpm would be limit for a long trip. That will drink enough gas on it's own.