T56 problems- clutch or trans?

An update.

Ordered a McLeod RXT twin disc and installed it. A bit overkill, but I can abuse it all I want and they say it will take it. Bellhousing dial indicated within specs, and is actually damn near perfect. Throwout bearing moves .440" like they say it should, and it has clearance to accomodate clutch wear. Everything looked good, so with the truck still on jack stands I threw it in gear to see if there were any funny noises. As I eased the clutch out I was watching the rear wheel to see if it engaged and as it did it wobbled a bit. Then it wobbled a whole lot. Long story short- I pulled the axle to inspect and found it was sheared clean off as it steps down to the spline diameter. Never thought that was gonna be the problem, but apparantly that was my issue at the track and I just happened upon the toasted clutch along the way.20161108_190647.jpg