I built a '29 Model A sedan delivery with a Hemi Ford (740 CU.IN.) and had to put two radiators in it. I used a electric pump made for a RV hot water tank. The rear radiator only had an inlet and outlet and a bleeder valve in it. If you do decide to do this it is really not that bad, just some more fabricating. Will you put a small radiator in the front or nothing?
Ken