Try driving a 1.3 FI sammy with 5.38 gears and a 6.5 tcase. At 65 it is pulling about 4700 rpms. The harmonics those rpm's create is nerve racking.
Wildgoody, I have kick 5.38's in the hybrid rear and a spare 5.38 pumpkin from CA. The zuk recycler had to pull quite a few diffs to find me one. You know where to find any?