I have been thinking about changing by rear gear from the stock 3:23 to a 3:73. How big of a difference does it make with the motor work I have and what will it do to my gas mileage? Thanks.

94' Z28 A4, balanced stock crank, Scat forged I-beams, speed pro forged pistons, stock bore, comp 218/224 w/ .537/.545 lift, 1.57" exhaust valves with 2.02" intake valves, full port and polish job with shaped bowls, 1.6:1 roller rockers, beehive springs, Hooker equal - length headers with Hooker Catback, B+M shift enhancer.

 

I felt a big difference going from 3.23's to 3.73's. One of my favorite mods. as far as gas mileage, I didn't notice any change in my daily driving. I'm sure if you did an all highway tank you would lose a little but not to much.