Can you tell me a little more detail of the simple valve modification?And does it compromise the power range?And lastly,,,does the GRT III trigger fit on the Benjamin 392? (I don't want to bother asking Charlie, I did read his website of what this trigger will fit: Benjamin Classic .22 BNS-AR-004, but from reading on PyrAir I couldn't tell if the 392 is the same thing as what Charlie was referring to)Thanks for all your great info.