most jets do not use a water pump.  that big white thing hanging off the back of the boat is a giant water pump.  you should have a block off plate where the water pump would usually be.  then its just routing a couple hoses from the pump, to a valve, thru the exhaust manifolds, into the motor and back out the exhaust for cooling.

I am thinking of throwing a cheap water pump on for now. Has anyone ever used an automotive pump? How long would it last? It appears to be my only option other than removing the pump. I wouldn't mind removing the pump, but all the cooling diagrams I see involve running the lines through the exhaust first, then into the motor. I have the original Berkeley logs with only one water input in the front and the only outlet is out the risers into the threw hulls. Can this setup be made to work?

I am thinking of throwing a cheap water pump on for now. Has anyone ever used an automotive pump? How long would it last? It appears to be my only option other than removing the pump. I wouldn't mind removing the pump, but all the cooling diagrams I see involve running the lines through the exhaust first, then into the motor. I have the original Berkeley logs with only one water input in the front and the only outlet is out the risers into the threw hulls. Can this setup be made to work?

There is virtually no difference in an automotive pump vs. a marine one. Not even sure a marine specific Olds pump exists. It should last several years.

In all honesty they run more consistent temperatures with a circulation pump. Plus you wont have to worry about belts and pulleys....

What we call a two-fer.