[Redline novdog]

Decide on the diameter of rear tire that you want to run, then look online for the gear/mph calculators. And yes, I'd be thinking closer to 3.07 with that 4-speed.

I'm with Picklito try a 31" or 33" tire before changing gears. A whole lot cheaper and if you do the math you can decide on a gear that suits you. I have had 33,31,and now have 30" on the back with a 3:08 rear and 3spd auto. No tach sounds/feels good.