Why not use the vacuum pump already on the engine? What ever you use, why not use the same source that feeds your brake booster, making sure the vacuum to the shut off valve is released after the engine stops. Electric is a good way to go also since you will not have to worry about rebuilding it, or catastophic engine damage from a failed pump.

AFAIK the vacuum generated by the engine's vacuum pump is about 20 in/mg. Vacuum is not measured in PSI in this application.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D