This is where I used to pull the pressure from. The location near the wear ring shows approx. 8 psi more than this area of the intake:
I went through several gages before I got this liquid filled AutoMeter. Mounted it on the dash. It's up-side down so I can read it at 105 or so with out having to search. The liquid filled gauge has next to zero bounce. PSI check valves don't work for what you want to do. You need to be able to read the gauge at speed.