Here are the 3550/TKO
ratios
The 3.73 rear gear is going to be short of your expectations as far as highway cruising (2700 rpm at 70) and IMHO will give you a pretty useless first - too low. 42-44 mph at 6000 rpm.
Consider a dif ratio in the 3.3-3.5 range with the .82:1 fifth.