Can you please post pics if the internals? if it works anything like the respirator, turning the adjustment screw in is higher and out is lower. You will probably need a pressure over 120 PSI or a ridiculously long dwell to cycle reliably (the shocker was never meant to use an LPR and the bolt sail dimensions show it).
An eigenbolt would've been a better investment (if you don't have one yet, if you do and are doing this for shiggles, knock yourself out), since it drops the operating pressure to about 140 PSI (10 PSI under the LPR's recommended setting according to the manual: http://www.paintballsolutions.com/pd...shockerLPR.pdf
A LPR in a shocker sounds like a good idea, but not only is it not necessary, it does practically nothing but add a lump to the body profile.