I am running 30psi on my Hustler at wfo. for 3 years with out any problems .Whipple recommends at least 25psi in the motor for the super chargers ,

that was my next question,
whats recommended? through out the power range? is there a rule of thumb,or a guidline from merc for stock? then, is there any guide for modified.
im running a water circ pump so maybe it doesnt pertain to me now but if i ever do a crossover............

I bought adjustable brass ones from McMaster-Carr for about $40 apiece.

What is the "rule of thumb" on water pressure?? Minimum?? Maximum?? I have heard 15lbs was ideal. In what situation might a higher pressure be an advantage?

would happen to have a pick???

Here's the one I bought from McMaster-Carr for ~$40. Probably the same one pachangalpina bought.

www.mcmaster.com

Is that a pop off valve .or do you adjust it like a fuel regulator where it bypasses all the time ?

From what I saw on a section view....it sets the spring preload.

That is the one that I use. Just set the spring pressure to bypass at the desired pressure. I would call it a pop off valve.

where is the best place for a pop off valve w/871 blowers ,crossovers no thermostst. i have one between the sea strainer and the oil cooler now,not sure if that is the best place to have the pop off valve.at high speed the water pressure drops way down to 5to8 on the guage.