Gears & Axles - Want to change 3.25 gear to 3.73 or 4.10 (A4)

So right now with a 9" running 3.25 gear with 315 35 17 MT Drag Radials. I am currently going through the lights @ 5500rpm. I dont want to go through any more than 6500rpm but not sure about what tire size to use with either gear to get that rpm.

Thanks

If you stayed with that tire size and went to a 3.73:1 ratio you would hit line at ~6300.

Simple way to calculate it: (Current rpm/current gear)*new gear = new rpm

(5500/3.25)*3.73=6312

Any calculators for changing tire height also? Looking for a good combination.

Thanks

good luck, Johnny
TRY this
http://wallaceracing.com/Calculators.htm