'51 3800, 216, synchro 4-speed, 5.14 factory rear gears. LT225-75R16 tubeless tires. Happy at 35 - 40 mph. Will do 50, but not happily unless it's pulling hard.
I've pretty much decided on a 4.10 rearend, yet to be installed, which will make 50mph easy and 60+ possible. That ought to bring the fuel economy into the tolerable range for daily driving, and eventually one of those 5-speed trannies from a Dodge Cummins, with one minor modification, will hide under the floorboards and make freeway speeds practical.
Dbone, for you or anyone who intends to use his truck as a daily driver I'd strongly recommend going to tube-type Radial tires on the original rims. LT7.50-R16 tires are readily available, will run cooler with less rolling resistance, and will in every way be better that original-equipment rubber, which belongs on museum pieces.
