[elhigh]

I'll be curious to know how well your vacuum gauge behaves; I installed a vac gauge in my truck a few years ago and was well pleased with it until it started to walk out of calibration.

I took it apart - which was a major undertaking as it had been pressed together, no fasteners - and reset its needle, but it walked out again. It lives showing about 10" vacuum when the engine is off. It came to rest at about that level both times, and now I just subtract 10" all the time. Even so it's useful to give a moment-by-moment idea of how well you're doing, but if yours does better, I'd love to know.