I have a 12 bolt 3.08 to 1 rearend with a 3 speed transmission (1 to 1 3rd gear ratio) and can do 70 mph all day long. The only drawback is it is wimpy in first gear. No free lunch, as they say. I would rather have a 3.73 to 1 rearend with a T-5. Now that is free lunch.
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission