My understanding was that the car balancer had a larger diameter pulley and the truck version was the one to look for to get the right fan speed.

From the e-bay listing of the adapter:

Caution: Do not use the 1955-62 PASSENGER balancer since the pulley is larger and will turn the pump too fast. (to identify this balancer pulley is 6 3/4" OD X 5/8" outside to outside edge)




1952 1300 Canadian 1/2 ton restomod
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