it could be cross threaded. I'll soon find out.
Just searched ebay (mopar dana pinion snubber) and found the dana 60 had 2 types. Mine is a late type (12/69) powr-lok 3.54 for a 1970 b-body.
I made an offer for it. There are several guys that seem to produce them, including a sox and martin type which looks like mine, but taller with more adjustment slots, and what looks like the front suspension bump stop on top.
Since my rubber stop is literally touching the tunnel right now in my garage, there is no travel at all!
I'm guessing the correct stop will buy me at least an inch to maybe 1.5" of clearance.