So I found five drain plugs for my 2001 5.7 but the Seloc manual mentions there may be another one in the "water tube" in the carbureted models. I looked all around don't see anything that looks similar. Am I missing something? Also, when I filled the engine with antifreeze, I poured the AF into the the large hose going to the water pump. After about two gallons, the AF started coming up through the thermostat housing. Would that indicated the thermostat is stuck open or missing? Or, is there a bypass to allow some AF to flow through even when the thermostat is closed?