Willy's PickUp truck gearing Question (Timken Rear end)

Hello, I have a 1951 Willy's PickUp truck with the original transmission, rear end (Timken Clamshell) and a factory Warn Manual Overdrive BUT the front end is out of a 1986 Chevy S-10 (Steering Column, Front end and V6 Vortec engine).

My question is gearing the rear end to get a higher speed, currently I get 55-60 MAX but I feel more comfortable at 50mph. I would like to improve the gearing to be able to drive it on the highway, 60-65mph.

Any suggestions are greatly appreciated!
Tony Fernando
Guilford, Vermont Attachment 1212

Nice Truck! I like the sideboards.

The Timken rear ends came with 3 gear sets - by far the most common was 5.38:1 which is what I have on my '48. And, you're right, 45 -50 is wide open and 40 is comfortable.

The Willys shop manual lists a 4.XX:1 ratio (I don't have the book right here), but I've not seen anyone mention having a set of them installed. (The real crawlers were 6;xx:1). The Dana rear ends were coming into use about 1951, so a Dana might fit into place - but they were still 5.38's.

Not a lot of options at this late date....