OK, OK In my haste to complete my car for the summer, and several other honey do projects Memorial Day weekend I put the T'stat in upside down
.
While the t'stat kinda, sorta worked in wrong, the water flow/pressure finaly caused the t'stat to break free from the ring that holds it in place. This must have happen Saturday when going to put gas in. The coolant flow would then cause the loose t'stat to get wedged in the t'stat housing causing a restricted water flow.
I have a mechanical temp gauge so I knew that wasn't the problem.