the air cleaner was off. I had removed it so I could get the water out of the carb (more water than fuel was in the bowls). after getting the water out of the fuel tank, cleaning and drying the engine overnight, I then cranked it up and let it idle for about 10 minutes, blipped the throttle open in nuetral and then up it went. I am thinking that there has to be a leak, because while there might have been a backfire through the carb, the fire was not just in the carb, the whole engine was a flame. wires melted, brake fluid resevoir melted, hoses burnt through.....

I have never had anything like this happen in the brief two months that the truck has been running, maybe it is a combination of things.

I have decided to replace the carb and completely rewire or replace (hoses etc) everything under the hood

thanks for the thoughts