I've got two 64's with 350/700r4 combos, one has 3.73 the other 3.42 rear gear. Both work very well and are around 2000 rpm at highways speeds. Love that quiet cruise...
Got several thousand miles on each. My transmission guy says they are updated to the newest parts and should hold up many more miles.
For reference, could you state your tire diameter too? I'm just thinking for future people referring to this thread. A 26" tall tire vs a 31" tall tire get very different results.
