3.91 gears for shorter 60 mph trips

I've got 3.91 gears in my daily '73. But I also have an overdrive transmission in the car.

For actual 'in town' driving it might be 'ok'.
The moment you get onto longer straight road or roundtrips, the rpm's can get old pretty fast.

Personally I would not want to drive 20 miles to a town with 3.91 gears in the rearaxle with a non-overdrive car.