Her is what I did. These pumps come with the air in and out in different locations, I chose this one because it fit my lay out. This is a Ford pump. It was designed for the vacuum brakes on a truck. Some out there look the same but supply much less vacuum. Most of these pumps made for GM only supplied vacuum for HVAC controls and cruise control so keep that in mind. It came with a flat pulley, I changed it to a GM to help keep the belt located.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
http://forums.maxperformanceinc.com/...1&d=1517252469
http://forums.maxperformanceinc.com/...1&d=1517252469