It could be the case that the heater core is partially plugged up. My dad had a 1960 Rambler years ago with exactly the same problem–hardly any heat at idle. Flushing the heater core solved the problem.
It could be the case that the heater core is partially plugged up. My dad had a 1960 Rambler years ago with exactly the same problem–hardly any heat at idle. Flushing the heater core solved the problem.