back when, chev. was bad about the mechancal fuel pump going bad and filling the oil pan full of gas. the last time it happened to me i was on a trip in a 1956 chev., 265 and the gas and oil started coming out of the dip stick tube. the motor was full of gas, but the motor ran great. put a pump on ,changed the oil and filter and the moter ran fine. it was clean inside though.