finding the right gear ratio ?

purplescamper said
i have a 73 scamp with a small block, 4 speed trans, 3:91 sure grip rear and im running 245/60/15 tires on the rear. its quick ff the line but when im on the highway im doing 4000 rpm ay 60 miles an hour.
what ratio would be good off the line and decent on the highway ?

with a 4 speed and 3.91s and about a 26" tire there is no way your doing 4k at 60.

you should be at about 2800 rpm.

i have an auto with 4500 rpm stall. 4.10 gears and 27" tall tires. im doing 2900 at 60.