Flowkooler water pump for 340 going into a 1964 plymouth valiant

it lists the core thickness as 2.25" but i don't know if that accounts for any stand off from the mounting brackets-- if there is any. the technical data doesn't show that detail.

anyway, the best way would be to install the radiator, install the pump and then measure the distance and select a fan clutch based on the room you have left.

if the motor is in the car, and you had the radiator sitting there, you could take your measures or mock everything up and know for sure.

but, because it's the old style waterpump, and it doesn't have an extended shaft along with the reasonable thickness of the core on the radiator, i'd hazard a guess that you'll be fine with a low profile fan clutch.