The loud square shafts all seem to be made of receiver tubing which is a super loose fit even when new and makes for a tank of a shaft. All of them that I have built for myself and friends have been 1 1/2x1/4" inner and 2x1/4" outer. Nice snug fit and only a slight clicking when the hubs are locked and the case is in 2x. I have driven many miles at near highway speeds with mine as have my buddies going from trail to trail with the hubs locked and none of us have had any issue so far.
Thats the same tube I use. I would recommend it for a nice tight fit. It will wear just as any other though. I built one using reciever tube, but it has since been used as a reciever tube. The reciever tube definately has more play than the 1/4 wall tube. I had to grind a groove in the inner pice to clearance for the seam of the outer tube.
