OK, just got the names of 3 more possible Pontiac class racer engine builders. A Pontiac engine builder who doesn't do class engines, recommended Competition Components.
https://www.buyracingparts.com/
For those on the East coast, he recommended Richie Hoffman. I think his shop is on Long Island.
https://www.facebook.com/richie.hoffman.520125
Richie also recommended Todd Hoven.
https://www.facebook.com/todd.hoven.3
I'll try to contact some of the big name Pontiac builders & see if any of them have any Stock/SS engines out there.