86foxbodyGT

I have a 302 5.0 with gt 40 heads upper and lower intake and 36# injectors converted over to mass air. My mass air meter was calibrated by previous owner. They also installed a calibrator. It has two *****, one i'm told is for the air fuel mixture and the other is total air. I found the exact same box online and it says you can use a DVOM to read and adjust the voltage to the mass air. I cannot find any instructions on where to start the adjusting or what it actually should be. Does anybody have any experience with this sort of thing?