I wanted to thank you again for your responses/help.
Now the search begins for a case without the groove...and perhaps a tail shaft as well (Mr. Munroe said this problem is often caused by a worn/damaged tail shaft snap ring/bearing/groove).
Your welcome. Thanks for the update from Mr.Munroe. That makes sense as to what causes it. Good to know. Good luck finding a good case. At least big block cases are pretty easy to find.
