I don’t see the need for different gears, seeing as your car only weights 2200 lbs. But as for the carb, why not try a 600 cfm for the street and the 800 for the track. If your meter is reading 12:1 at crusing speeds, you are running rich, but I am sure that I really didn’t have to tell you that. You could try re-calibrating the 800 intermediate circuit.

As for another 350 engine, forget it. If you have the huffer, use it.