I am looking to install a water pressure gauge in my boat because I blew an exhaust coolant hose and burnt up a manifold and didn't know until it was to late. So my thought is if I install this gauge I would see the pressure drop and know something is wrong. Am I correct to install the pressure gauge just after the pump? Will I see a pressure drop if this was to happen with my new tube headers?

i also picked up a pressure relieve valve that is supposed to relieve excess pressure over 15lbs. I'm also assuming this goes post pump, am I correct with this as well to reduce possible pressure spikes?

Is this a good idea or design? Any input?