[Mike C]

Or taller tires. Taller tires can make a dramatic difference. But the reality, is the 3.73 are quite a bit of gear for that 307 to run on the road. My 69 short step with its 307, TH350 and 29" tires on a 3.07 rear gear is happy on the road at 60-65 but 70+ too much.

For now, a set of 3.07 gears would help a bunch with driving on the road. Another 50 lb/ft with a 350 would be nice as well. A cam swap in the 307 might help as well by extending the upper rpm range 500-800 rpm higher.

Just no cheap and easy solutions.