318 complete combo suggestions...

318willrun basically nailed it. Hwy. gears of 2.94 or lower and a minor cam change at best and of modest size.

Hwy. driving here is limited and I can live with 4.30’s on a 26 inch tire. Not so else where in this country and even more so in the middle where there is a vast distance to be covered to the next town.

The only other option is a overdrive. Then there is minor math involved to get to the final drive ratio for the long cruise.

4.30 (gear) X .69 (O.D. Ratio) = 2.967 final drive ratio.
2.96 by tire diameter by cruise speed equals XXXX RPM.
(Minus converter slip.)
Get to a on line calculator for this.