Gears would be the cheapest option I think. 3.42's offer decent grunt with freeway cruising. I imagine you're running a 28" tire? Check out
WALLACERACINGCALCULATORS.COM
they have all types of calculators to help you figure rpm/mph with gear ratios and all.

Last edited by Hollow65; 08/29/2014 12:12 AM.

I can explain it to you, I can't understand it for you.