cranetruck

I'll say, keep looking, you need to be able to see the reading while driving so a full scale of 10 inches of water should be good or the equivalent in cm of water, which would be about 25 cm of water full scale.
My readings were all below 20 cm of water.

BTW, the Magnehelic gauges can be connected to read pressure, vacuum or differential pressure. There are 1/8 NPT ports for all these options.

Bjorn
Virginia's Blue Ridge Mountains
Avatar: XM757 in OK prepared for 1,000 mile trip home. Part of 6,000 mile journey in 2006.
1968 M49A2C modified with 1960 M756A2 truck bed and 1975 HIAB 765A knuckleboom. Heated dual tank system for biodiesel/veggie oil use.
1969 Ford XM757 8x8 5-ton truck tractor W/W, the "improved" MV.
"Some things can't be made better, just differently......a lot of things actually"