[kenn]

Hello
My 72 has a valve in the 5/8 line (feed to core) that opens and closes with the hater switch in the cab.
If you don't want heat "ever" than you can remove the lines at the intake and at the radiator.
Cap both lines.
The coolant in the block rotates thru the pump(in one mounting leg and out the other)and when it gets up to temp the thermostat opens and lets it out to the radiator.With the cap on, the coolant stays in the rad untill the stat opens and starts flow thru the rad and block.
I hope this helps.
K.E.N.