Could be Stuart. If you recall a few months ago I was posting about the vibration I was feeling at low speeds. I ended up disconnecting the driveline and putting the front and intermediate u-joint in phase. That pretty much fixed the vibration. Since then it has been sitting. I didn't notice the grinding when I first drove it following the prolonged sitting period. I drove it for about a mile before noticing the grinding and it is a little intermittent. I'll check out the intermediate bearing. I'm stymied. The rear end was not rebuilt and it was fine before I did the restoration. The u-joints are new. Tranny and rear end fluid levels are both fine as well. I've noticed if I drive it at slow speed (3rd gear and lower), there is no grinding. I'll check out what you mentioned. Thanks.

1953 Chevy 3600 3/4-Ton