While we were waiting on the engine to come back, we sent out our radiator to be flushed and pressure checked. Because of environmental regulations regarding the chemicals used to acid-dip, a majority of radiator shops can only boil and flush brass radiators today, even the coil cleaner we used to use is taboo these days. We found a shop in nearby Albany, New York , Empire Auto Radiator, who was able to do an excellent cleaning job, despite the milder chemicals they are obliged to use.
Our current radiator is the same general design as the 1934 flathead radiator: dual inlets for the dual puller-type water pumps on the front of the cylinder heads, and dual outlets to connect to the lower water outlets/front motor mount brackets attached to the water jacket on either side of the timing cover. Empire noted that it had been upgraded earlier in life, using pre-war Chevy tanks and a three-row center core, so the cooling capacity was plenty large enough.
Even so, we re-installed our add-on electric pusher fan rigged to a toggle on the dashboard so the driver could monitor the water temperature by the dash gauge and turn it on or off accordingly. We installed a 16-pound radiator cap with a safety lever to raise the boiling point of the coolant a bit. The higher the pressure of the cap, the longer it takes for the coolant to boil. This is why you see some NASCAR teams using ridiculously high pressure radiator caps; you can raise the boil from 212 to over 230 degrees by holding in the pressure.
Of course we replaced all the hoses and clamps too including the overflow hose. All four hoses were simple 1-1/2-inch elbows so we bought two Chrysler slant-six upper hoses for the inlets and two Chrysler 318 lower hoses for the outlets and trimmed them to size. Overflow hose was basic 3/8-inch neoprene fuel hose. We have not yet installed an aftermarket overflow tank, but we may do that later this year when we see how the 16-pound cap works out.