Fuel in engine oil

I agree with hangnOut in post #2
The mechanical fuel pump has a diaphragm in it that has gas sitting on it almost all the time. So long as the fuel level in the tank is higher than the pump, there will be fuel in the pump. If the diaphragm has a perforation in it, the gas can find it's way into the crankcase pretty easily. The fuel in the line between the carb and the pump can also drain back through the pump, although the checkvalve ought to prevent that. If the Edelbrock bowls go dry in a very short period of time, it might also be a bad carb, as in a cracked mainbody, although that would be highly unlikely.
The pump is easy to prove