What carb do you have on the engine? If it is a holley, with all that back firing, you blew out the power valve. I am not sure about the other brands but I've had some holleys that this has happened to. It sounds like your issue is the carb flooding the engine. Again, if holley, will need a new power valve and probably needs rebuilding, since it backfires when cold. There are options for power valves that won't blow out if you get a backfire, look for them.

In the meantime, take all the plugs out and let the cylinders dry out. How is the oil? Does it smell like gas? If so, that will need changing before you do anything else. You can run the risk of destroying bearings and everything they touch. Once you've got the gas out of it, do you have a different carb you can try?

CM beat me to the bunch about the carb....