GNJ

Thanks to everyone for your responses.
Offthefront - your right they are left hand rotation. I think I am going to have to pull a pump off and check the impeller inside to see or know for sure exactly what I have.
On the mercruiserparts web site, I see the water pump merc number is the same (#8504541) for serpintine belt motors and regular belt motors. - Gary

offthefront

I checked today .... the 502 MPI pump does turn clockwise and the Carb version turns CC (left hand) .. but they are the same pump ......m

Pwrbt33

Bolt it on and go fast. Theres not a problem.

John