Hp500 Circulating water pump
 

Hi
is there a replacemen circulating water pump that can fit on my hp500 without buying it at mercury dealership ? I know that gmc put some 8.1 and 7.4 in there truck few years ago.

You could go with a Sierra brand one, but I would go with Merc.
I would not use an automotive recirc pump. The internals on auto ones are designed knowing it will have AF and they don't have SS internals.

Using a marine pump is really critical if you don't have closed cooling. The seals are different and the automotive pumps need AF to lubricate them. I you have seawater cooling, you better make sure you bilge pump is working, because you will need it. I've burned out a couple of water pumps on cars running straight water before.

Ive used these before with no issues,

GLM Products Inc - Water Pumps