Inliners International Forums General Discussion Drive Train Anyone successfully adapt a T-5 to a torque tube?

I think that inline overdrive you are talking about (or were...) would be a Ruckstell. These were people who made 2-speed rear axles for T-model Fords as well.

In addition, there was in the T-model range, probably from the factory, an 'underdrive' for trucks that went into the driveline. It can be reversed (a friend of mine has done that on a K-model Ford) to give a taller ratio.