JCS,
The TKO is excellent, although it will take a few K miles to loosen up. The TKO jump from 4th to 5th is big for a small block - the TKO-II has a .82 5th vs. .68 for the TKO. Either has more than enough torque capacity, so does the T-5.
I have a 3.54 diff, with a TKO, there is a spot between 60 and 70 that is awkward because of the 4-5 gear spacing. For crusing it revs a little to much for 4th, grunts a little to much for 5th. Solution: cruise at 70.
