I have short shaft water pumps on a 51 and 37, both with 261 engines.Both have the stock fans,using a spacer between the fan and pump pulley.About an inch or so clearance between the fan and radiator and the blades clear the pulley by a hair.I also modified both radiators, moved the mounting flanges a little to get the radiator foward as possible.The lower water pump and fan position leaves something to be desired when using a 55 and later block in a original 216 truck.
