The fact that you never use fifth gear is the surest sign that you are desparately in need of lower (higher numerically) gears in your axles. Get at least 4.10 gears. If you have a 5-speed manual tranny, and fifth gear is an overdrive gear, then I'd consider even getting 4.56 gears in the axles.

1977 CJ-7, fiberglass body, AMC 360 w/ headers, DUI ignition, Edelbrock intake and Holley 4150 carb, TF999, Dana 300, 4.56 gears lockers, York air comp, 4" susp lift, 2" body lift, BFG 35" M-T tires, Megashifter, AGR pump & box, REP8000 winch.