I did the 3sp+od on advice from the dearly departed Jack Halton, past president of Inliners.org. I popped in the 3.90 from a '57 truck, it's a 3.90, just like what you have. The math is .70 (that's the overdrive) X 3.90 (your rear end gear) = 2.73. With 215 85R16 radial; tires I'm going 70 mph @ 2000 rpm's. That's with a '56 235. See below....
~ Cosmo
1949 Chevy Half Ton
Rocinante, like Don Quixote, he is awkward, past his prime, and engaged in a task beyond his capacities.
"...my good horse Rocinante, mine eternal and inseparable companion in all my journeys and courses." ...Don Quixote, Cervantes
"If you come to a fork in the road, take it."...Yogi Berra
"Rudeness is the weak man's imitation of strength." ...Eric Hoffer
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