Raw water cooled engines listed in the subject line. I will be plumbing in mechanical water pressure gauges and would like to know two bits of info.

1. What is the pressure range from idle to rev. Limiter @ 4400 rpm? I did not find the info. Here nor in either the Clymer and Mercruiser manuals cooling and general section.

2. Where is the best place to plumb the gauge's water line to? I'm looking for specifics please. I've seen some on other engines say "intake". When that is said I think the plenum on top of the intake manifold and obviously there's no water there. So again please be specific and detail whether a plug is removed or the like.

As always, thanks for any help you can lend.

Can someone please provide the requested info in #1 above? Thanks!

Your pressures should be around 2-5 Psi at idle , no more than 15-20 at WOT. Most all factory gauges are tapped into the engine block drain. Which isnt such a good idea,
Ive had to replace 4' of hose because it was plugged with rust and sediment from the bottom of the block.

Thank you very much for the data points, they'll prove useful for sure. I removed a plug from the thermostat housing area where the 4 hoses come together above the crank pulley to install the bung.