What diameter tires are you using?
A 3 speed transmission with a 3.08 rear end with 28" tires will be nice on the highway. It will not be nice with a load on a hill in first gear, nor with one tire in a hole. Your clutch will slip like crazy while you try to milk it to keep the engine from stalling. I speak from specific experience.
Shorter tires will help this situation, but it will cost you on on highway speeds at a reasonable RPM.
As they say, no free lunch.
Carl
