[Tx Firefighter]

Dubie, my 454 truck had 3.73 gears in it. I could not make myself drive at speed on the freeway. 70 miles per hour was too much.

I traded a board member straight across for a 3.08 rear. My mileage increased 5 miles per gallon (up to 12) on highway driving.

I have actually experienced what pieceparts has on an overdrive vehicle though. My 83 truck came with 2.73 gears and an overdrive. The mileage was horrible. When the 700 went bad, I replaced it with a non overdrive Th350 trans. The mileage actually increased without the overdrive because the engine didn't have to work as hard at highway speeds.

For your 3 speed truck though, 3.08 will make you a happy man.