[smallblock450sl]

Might try this....your fuel pump has 3 lines, from the tank,to the carb and the 3rd from the engine (it is the pulsar line and drives the fuel pump with crankcase pressure). Take the pulsar line off and blow into it back toward the engine. You should feel no restriction! If you do, take the oil fill cap off and cover with a rag, then use compressed air to blow all the crap back into the engine. Suggest changing oil (1 qt only) and maybe try pure synthetic oil (doesn't seem to attract mousture). Also add some "heat" or other gas addative. The gas we get now adays just attarcts mousture. Good luck.