4 speed or 4 speed OD?

Id stick with the 4 sp. I have drive both and the "3+1" OD box is just that: a 3 sp with its wide gears (and no convertor torque multiplier) and an OD that seems to just slow the RPM's down. Seems like you could go faster in 3rd (1:1) than the OD 4th as your motor never hits its power band. The 4sp had the 'correct' gear spread and a solid 1:1 4th. With a 3.31-3.55 rear, it was still a nice cruiser, rare 3.73 (?) a 3.91 was a little tight, and the 4.10 and 4.56 were just off the chart truck gears.