With 33 inch tires, 4.88 gears, and 4.7 low range my truck runs about 19 mph at 4,000 rpm. Most of the time it is OK, but the higher transmission gears are not always designed for the same amount of torque as the lower gears, espectially overdirve (5th). Having a single 4.7 is way better than stock, but having more options would be better.
if i'm not mistaken, the order of gear strength from strongest to weakest in a toy tranny is 4th, 3rd, 2nd, 1st, 5th, reverse. with 4.7s in a single case, 4th gear low would essentially be a bit lower than 1st in high range. no problems with gear spread IMHO, though having more options is never a bad thing!
