742 clutch type sure grip
It shouldn't have bolted to the housing if they weren't aligned unless the axle was too short. I haven't had any experience with Yukon axles but I have read you can't use stock A-body brakes with them for some reason. Don't know if that's true or not or if has an affect on your problem. Hopefully somebody else will chime in.
Here's a page on Moparts tech archives that shows some pics of the 2 different sure-grips and gives descriptions. The cone type is first so you have to scroll down the page a ways to the clutch type.
http://www.moparts.org/Tech/Archive/axle/13.html