Hot Hubs!

[Americanrider]

My first clue was using 1/8 of a tank to drive accross town. The motor was running fine but no grunt. I pulled into a parking lot and grabbed each hub with my bare hands. The rears where cool but the front ones where very hot all the way down to the locking knobs.
(RED HIGHLITED AREA ON PIC)

I eased it back home and put the ol' girl up on jacks today. I pulled the pass side and the bearings are good, plenty of grease. If anything the lock nuts where a hair on the loose side. I spun them off with a screwdriver, didn't need the 44 hub socket at all.

The next thing I noticed was the backing plate/Caliper mount was a bit loose on all 6 bolts. (see yellow arrows) I could move it about 1/8 of an inch back & forth. So... here is my theory...

If the backing plate shifts then the caliper binds, dragging the brake pad on the rotor and causing heat buildup. Would the brake pad heat travel that far down the hub? Tell what you think? Am I missing another cause? So far I have only pulled the right front. Will do the left side tonight and re-post.

This is on my 67 K20, D-44F from a 1975.