off the top of my head (and probably not very accurate)

std 2-3 psi
-31 7 psi
-34 14psi

thats their opening rate. so if you set them to half hole preload with no bleeding, thats what they'll hit.

obviously you acheive the higher boost by bleeding some air off with an amal/bleed valve

the -3x bit is the last 2 digits of the part number, ie 32432434234-31 (made up number)