Its been to a tuner twice in the last 18 months its going again in a few weeks for a tune up on the rolling road, how can i test weather its a -31 and what is the difference between a -31 and standard item, what the gains etc, when i had the boost valve (forgot the actuall name) the one with a spring and ball bearing in a seat etc, i had it set to 15psi then and it would boost fine and hold 15psi no problems, but want to adjust it on the actuator but just havn't got enough adjustment left, is it ok to shorten the rod by cutting a few threads off, the actuator holds pressure fine and doesn't seem to leak either, Cheers SEB