Here is some more information on tourque tubes - it adds very little to 53moneypit's information.

The torque-tube was used on 1/2 ton Chevrolet and GMC trucks through the 1954 model year. I heard that it is still used on C4 & C5 Corvettes and modern Aston Martins (I could be wrong on this).

Tim

http://en.wikipedia.org/wiki/Torque_tube