Hub issues

Yes please do have the hubs pulled and marked. I replied to your PM. My pullers apparently are noy American steel LOL.  I am putting a twin-grip in it along with 3.55 gears

Thanks!

Just to add a little to Bill's excellent answer:

1) A factory new hub has NO splines inside. It is slightly softer than the hardened axle. Splines are formed in the hub when it is first bolted to the axle, which is why there is a "stick out" measurement for initial installation (or installing a new hub on a used axle). I've never bothered with the stick-out measurement when putting a previously installed hub back on an axle, just torqued it down. With a new hub you may need to exceed the factory recommended 250 ft/lbs of torque to get the stick-out right. Once the stick-out is correct with a new hub the axle nut should be loosened then torqued back down. It's still a good idea to check the stick-out, but it should be correct as long as the hub is returned to the axle it came from.

2) Bill's last reason for a hub slipping is why most only spin the right hub. Open diff, all power goes to the spinning wheel. When it suddenly finds traction... Once one has spun it slips, and an open diff will give the slipping wheel most of the power. It's possible to spin both, but you'd have to be running a spool or a locker. I'm not sure a locked up limited slip would do it, but might. It would be possible to spin both if one wheel suddenly caught traction and spun then the other did the same before you let off the gas. Possible, but not likely. Once one spins you'd know something was wrong and let off the gas. On a drag strip the car would start to go sideways as one wheel started slipping, not a situation to keep your foot down! A rock crawler could get into such a situation, maybe...

3) Hubs spin due to age as well. In the last 2-3 years I have had several people report spun hubs on even 196 powered 63-64 Classics. People aren't banging on them, they are just over 50 years old! AMC didn't spec a re-torque interval as the cars really weren't intended to be around more than about 10 years/100K miles. 20 years/150K would probably be a good re-torque interval. Of course by then you'd have had to replace outer bearings and/or seals if the car was in regular use. At that point it's Bill's #1 reason for spinning a hub -- axle nut wasn't torqued properly (messed up on a prior service) or could be #2 - used hub or got the hubs reversed (which I guess would be "messed up"...). Bottom line is if you have a 60s or even 70s car and not sure if the hubs have ever been off it's a good idea to loosen the axle nut and tighten back down to 250-300 ft/lbs. Factory says 250, 300 shouldn't hurt, but don't go overboard. More will just put additional stress on the end of the axle. In the mid 80s someone at AMC messed up and doubled the torque -- 500 ft/lbs -- for a few months of production. 2+ years later some Eagles started breaking axles in the center of the hub. Still run across one of those on rare occasion. More isn't always better!!