OK, I know where to hook up a water pressure gauge on a standard engine...usually at the block drain or some like the intake. But...where do you hook up the gauge on a closed cooled engine such as the 525EFI and 496 engines? Hooking a pressure gauge up to the same location will not tell you if you have a water restriction or pressure prob. because the raw water will not be read by the gauge. So is it best to hook it up right after the sea-strainer? or after the raw water pump? Where did boat builders install on these engine setups? Thanks for the help.

I would definitely go AFTER the seawater pump. If the impeller goes south you want to be able to see it. Before the seawater pump would only show a restriction like a plastic bag on your drive .

I had mine right before the exhaust

Put your pressure gage at the output of the seawater pump. After all, pump output is what you want to monitor. Differences here will alert you to a bad impeller, intake restriction, or even a blockage in the heat exchanger. There's not really any other place to put it.

On the 525 there is a pressure sender on the top starboard side of the oil cooler on the back of the motor. We take this sender out and install a tee in the cooler with the sender on top and the gauge to the side. This will show you the same pressure the computer see's and is before the water passes through the coolers.
Steve Schmidt
Competitive Edge Marine

Ahhhh, Yes, thanks Steve and everyone else! I definitely want to keep track of the raw water impeller.