Quote:

Does it really matter which way it flows through the heater core?



on my non-a/c 68 DART it had two 1/2" lines with no valve, water flowed all the time. heater box closed the air/heat off.

over the yrs I know I reversed the flow thru the core a couple times patching up the hoses or with an engine R&R.

allways worked with plenty of heat, even during the summer.

I remeber thinking why is there no valve on it when I got it... maybe it was MIA?