What is the maximum height I can mount a sea strainer in the bilge relative to the raw water pump?

What is the indication for a pressure relief valve/water dump?

typically you dont want to mount it higher than the pump , lower is better. it helps on dry start ups. makes for an easier prime.
if thats difficult than keep it as close to water level outside of boat while boat is at rest.
the water reliefe is usualy for boats that run fast. the reiefe helps purge the water system of spike pressures upon reentry.

Hey, thanks Monstaaa! Makes sense. Still trying to find a good location to mount these in a 382.

What is considered "fast" enough to need a pressure relief valve and should it be before or after the strainer?

usuallydepends on the amount of pressure your seeing on the guage. also affected by drive height and style of pickup, in bravo apps.
anything running in the 90's should have one in my opinion.

it just causes less stress on your water/ cooling system

In my 302 Formula, they are mounted to the center stringer as low as they can be. It came from the factory this way.

Thanks for the input, Cuda. No stringers in the FasTechs!