Several questions come up as to which waterpump a 60ºV6 should run. Here's a short run-down of what you need to know:
The engine timing cover style will determine the type of pump that is on your engine. Chances are, whatever the engine currently has is what it will continue to run.
Is the OEM waterpump pulley currently Smooth? This is an Anti-Clockwise waterpump.
Is the OEM waterpump pulley a grooved serpintine or V-belt pulley? This is a Clockwise waterpump.
History:
By the late 1980s, most engines were already running the anti-clockwise unit.
The anti-clockwise systems are best to run for just about everything. When running Air Conditioning, a benefit of this is less idler pulleys required.
The benefit of a clockwise pump and timing cover is really (in our opinion) for engine that is being built to appear correct for the Era including carburetor (say a car that was produced in the 1950s through 1980s) then changing over the the clockwise timing cover may be a good way to go.