I have been looking into a Spa Technique rail pressure gauge for my 03 and for a friends 04. 5. Does anyone have these and have you maxed the gauge out at 30,000 psi??? The way I understand it the OEM sending unit that your using to get the signal is the limiting factor. Has anyone else changed theirs out for one that will increase the gauges ability?? Or should I even be concerned about doing this??