Radiator is out, what can I do in the meantime?

Interesting about the heater lines. Well as luck would have it, heater lines have been bypassed and looped to each other. So heater does not work. I am guessing that the heater core leaked and so the previous owner just bypass it.

Replacing the heater core is on my list. However summer is ******* hot here is So Cal. So I have no real hurry to get it fixed.

Good time to go through the system while the rad is out. It's really cheap insurance to replace all those items