I swapped in the 4:11 gears (pumpkin) from a late 60s truck and I love it. Not only will she cruise nicely on the highway but to my surprize it's much better to drive in town. Difficult part is finding the 4:11 diff, I'd place an ad here on the bolt.

It's easier to get forgiveness than permission!
1946 1/2-Ton Chevy
1953 Chevy 3/4-ton Factory Stakebed