I used a 1953 235 Chevrolet car water pump 3/8" groove with Dave's adapter on my 1956 Chevrolet car engine in my 1951 suburban .
I know I changed the harmonic balancer as well , would have to measure it, don't remember the size of it.
rock auto water pumps

If he uses a long shaft pump , the radiator will have to be moved forward for fan/radiator clearance, if it already hasn't been done.

Tim



1951 3100 Chevrolet
1951 Chevrolet Suburban Carryall
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