Here's a gear calculator
http://www.onlineconversion.com/bigger_tires.htm
With it you can plug in your numbers and see what your different options will do as far as RPM and MPH.

looks like the 0.73 OD on the NV4500 will take you from 45 ish to about 60 mph at 2,500 rpm (with 36"? tires). That seems plenty unless you've got more power and good/better brakes too.

Plug the numbers in and see what you get and what you can live with.

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-