I pull the thermostat and run a shop vac hose (or whatever I have that fits) from the Water pump outlet to the garbage can. So that's the 'Return' line.
Pull one of the heater hose lines and hook the other up in it's place to bypass the heater (and it's small passageways)

Then I pull the block petcock/drain and thread a fitting in to hook up the 'supply' hose from the sump pump.
Your local hardware usually has the brass fittings needed to adapt from one size hose ID to another.

In at the block drain Out at the water pump outlet.

If you have a way to block off the rad hose lines you could use the heater hose 'ports' I suppose.
I just went with what was easiest on the rig I was working on...

I usually start with hot water from my H2O heater to help with any grease or oil.
In the end I just wanted a way to circulate the water for hours without having to run the engine.


Give me ambiguity
or give me something else