amalinze wrote:Half a face? Usually its divided up into thirds, approx One third vacuum, two thirds boost.
actually the autometer guage i have
![Click to view larger picture](http://www.autometer.com/img/products/5401_d.jpg)
their boost only is 0-35 same as the above but without the vac portion so full deflection but we dont need 35psi
other manufacturers i have seen a 0-20 which would be ideal