Is there a difference between automotive circulating vs marine. It`s for a BBC.

From what I've seen the auto pumps are bigger which puts the belt out further and also I believe the internals are different to prevent corrosion being its circulating raw water and not coolant. Hope this helps.

Marine version gets you stainless steel impeller and back plate.

Corrosion resistance - marine pump will have stainless or bronze components while auto will have regular steel and cast iron parts. There are long and short versions of marine and automotive pumps for pulley spacing.

Many times, it is worthwhile to put new seals and bearings in a used marine pump than to consider it dead.

MC

Thanks guys well last year I put an Automotive pump on ran fine last year, this year is a different story ,so far new thermostat,impeller. I have had so odd readings for my temp gauge, I`m heading up to the boat tomorrow to pull so hoses to see if there is any blockage . I think I was foolish not to spend the extra, but some of the guys said it would not be a problem, see what happens when I listen.

If you run in fresh water there would be no issues but if in salt.....

The seals are different too, if you run an automotive pump with straight water the seals will burn up. I learned that the hard way.

correct...

Thanks guys I went to boat today and pulled all the hoses and drained the block to see if any debris was there one small piece in the block all was good. The last hose to be pulled was the hose coming from the drive, low and behold the plastic hose was cloged and a small crack. I was able to put the hose back on and check for leaks.

I let the boat idle for a good ten minutes with the temp holding right at 150*. I`ll be going back tomorrow for a run and check on things.

Thanks

mark