382 davco coolant( heat) lines

That "overflow reservoir tank line" in your picture is a low flow line that is primarily for funneling superheated vapor to the radiator and would not be suitable for your intended purpose. You would be a lot better off to "T" into both your cab heater lines at or near the engine block and run them direct to the Davco filter. Even if you shut off the heater lines during A/C season you don't want to heat your fuel then. I was told the Davcos I have used have a thermostat built in to protect from overheating the fuel and therefore should be on their own circuit and not in series with anything else.

 

What part of the world are you running in?

 

Use the return fuel line to heat the fuel pretty simple

 

Using return fuel is easier but running in real cold areas I prefer using the coolant.

plus the newer engines don’t return enough fuel to warm jack …..

 

I don't have any heat on my 382 and run Michigan Ohio pa all winter no problems as of yet

 

That's why I was wondering where he lived/ran. Lower 48 with a S60 shouldn't "require" a heater circuit on it.

 

davoc has diagrams showing the hookup for any engine doing internet search. pretty simple heater hose coming off oil cooler to davoc return to bottom of water pump or the return pipe coming off the bottom of the radiator.