I just called the shop to inform them that I was coming in to do a tune-up on it and the shop foreman told me he took off the valve cover and one of the retaining nuts on an exhaust valve had backed off. He adjusted the valve cold to the same as another cold valve and he said that cured the problem. I am still going to go and do the tune-up and re-adjust(or make sure) everything is in spec. My theory stated on page 1 turned out to be right. I am glad it was something easy. It was my fault.

52 Chevy 3100 5 Window, LS Swap, 4spd Auto, Vintage Air AC / Heat, CPP Power Front Disc Brake Conversion with bearing upgrade, Power Steering Conversion, LED Tail Lights