The Stovebolt Site Forums The Shop Area Driveline Hydramatic Top Speed?

Take a look at Patricks Antique Cars & Truck parts

When get to the page there is a separate side scroll bar,scroll down to page 13 about half way down, you will see a picture of a pickup with the word NOW in the picture.
High-Speed Rear Ends
'55-'62 pickup 1/2 ton 3.38:1 ratio
ring and pinion installation kit

You should be able to cruise at 65-70 mph with 3.38:1 ratio rear end. And get pretty good fuel economy.

After calling Patrick's.
Let me know what you find out.

Thanks,

Added more 3.38:1 ring and pinion installation kit links:
ringpinion.com
tomsdifferentials.com