Steve - the "comfort" can't be improved much, these ol trucks are noisy at speed regardless and the brakes are retro-tech that you need to make allowance for, especially when towing - 283's don't mind cruising at high RPMs, so don't think that hearing it wound out is worrisome, I cruise mine at 65-70 with the stock 3.90 rear and 3 speed, only thing that bothers me is the noise, and that's mostly road and wind noise and dual exhaust
that said, any overdrive trans will drop highway RPM nicely and still allow good pulling power for towing
Bill
