OK Ive got a serious problem.

two engine fires in two days. No apparent fuel leaks from the carb (holley 600 vac sec).

Been running it for two months with no problem. Had some water in the fuel and caused the truck to shut off. got it cranked and up in flames it went. got everything cleaned up and made sure I had no leaks and no fuel sitting on top of the engine. cranked it up. ran it down the road. ran rough @ low rpm's but with no other problems. let it sit for about an hour and tried to crank it. cranked fine and then up in flames again.

Could there be anything iternally in the carb causing this, or do I just have a fuel leak that I just can't see.

all thoughts welcomed...