My engine got up to 250 degree's yesterday when my belt broke. I shut The engine down as soon as I noticed the temp climbing. I have a 355 with a 750 edelbrock perf. carb on top. I put a new belt on today and started it up. I let it idle for 20 min. and it was fine. Now when I rev it up the carb pops like compression is runing back though it. It only pops 3 or 4 times and then it stops.I took the vavle covers off and there is no broken spings and it seems to be working right. Does anyone know what this might be. Thanks

 

This is a stretch but is it possible you damaged a plug wire and it's cross-firing? Other than that, check for anything that would cause a cross-fire, possible cracked cap.

 

The wires are o.k. and so is the cap but thanks for the suggeation.

 

damaged valve maybe.

 

I found the problem. burnt head gasket. Thanks