http://www.csgnetwork.com/multirpmtirecalc.html


Well i found a link. Just enter your desired speed, rpm, final drive, and diff gears and it will tell you what size tire is needed for that example.

I choose an 80MPH target with 4.56 diff gears, 3000 RPM and 1.00 final drive.

It said that i would need a 39" tall tire. Which i am wanting to use 40's. I guess i have made my choice, SM 465 it is. Thanks guys.