Originally Posted by Bill Marlow
What ratio would you recommend for this truck with the way I intend on using it?
What is your tire outside diameter?
Transmission ratio in high gear?
Current rear axle ratio?

Plug it all in here http://www.onlineconversion.com/bigger_tires.htm last one on the page.

You'll probably want 1,600 rpm at cruising speed, be it 65 mph or 70, or whatever you like. That should be OK for the 6-71 and the intended load, and result in reasonable mileage and reduced "noise" if you call it that wink

You'll want to turn no more than 2,300 rpm at your fastest speed So if you might need to go 80 mph every now and then for a short bit plan on that too.

Might be you need a single speed rear axle to get fast enough ratio choices.

Would also be nice to have a Roadranger 10 or 13 speed overdrive. If so then I'm guessing 3.54 axle gears with the 0.80 OD in the Roadranger.

How fast do you want to travel, and what are your current measurements and ratios?

Grigg


•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
---All pictures---
"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-