StingrayL82 wrote:
My tires are 225/75-16 (29.29" tire diameter), which is the closest thing I could get to the original 8.00-16.5 tires. Funny thing is that, per the service manual, my rig should have had a 39-tooth speedo gear, but when I had it rebuilt, we found a 38-tooth. Having done the math, the 38-tooth gear will work very well with the new tires, to within 1/2MPH.
Interesting choice. I thought about going that route, but with a width of 8.9 inches, I thought that it could pose an issue in spacing between the duals. Of course, I was forgetting the fact that my replacement wheels would likely have more offset, coming from a vehicle that ran 235/85R16 from the factory (late 80s D350 pickup).
How is the spacing between the rear duals with the 225s? What wheels are you running?
Another thought I had was that we drive much faster these days than the 55 mph era. 55 is just plain dangerous here in the desert southwest, where the speed limits are 75 and 80. I looked for the tallest tire I could fit without rubbing, while still being narrow enough to ensure clearance between the duals. This gave me LT215/85R16E as my choice. 0.9 inches taller, and 0.5 inches wider. This reduces my final drive ratio by about 3%, and keeps me just under 3,000 rpm at 65... and in my first couple of trips, 60-65 has been my travel speed.
