I'm hooking up my stock deluxe heater in my '57 with an LS 5.3 engine. Where do I route supply the hose from the engine to feed the heater assembly? I would guess the valve, but so many times in this project I've guessed wrong. I know which tube on the motor's water pump is the "outie" & how the hoses are routed between the valve & heater core but am not sure which hose goes where. Thanks.