He is correct, if your block/head is clean and the radiator is up to snuff the pump is not needed on a black era car. This also assumes the fan is in good shape and the belt is not slipping so as to pull sufficient air through the radiator when forward speed isn't up to the task. The coolant will circulate without the pump. Farmall tractors (the smaller ones) didn't use a pump either and they worked many an hour in the feild without one.



The problem is that most original radiators today have been subjected to a few too many thermal cycles and the fin to tube contact is not good enough to transfer heat at a pace fast enough to prevent the thing from boiling. A new flat tube radiator (or a recore) and a clean block and you would be hard pressed to get the temp to the middle of the moto meter.



I may catch flack on this but my feelings are in line with Marks, a waterpump is like cough syrup. It may reduce the symptoms but you still have a cold.