Surge Alamo vacuum pump. I ran it on a vacuum tank so I regulated the vacuum to 19" max. If you want to go higher, MountainVan uses these pumps to get 23-24". For that you would need to open the oilers more and use a releaser. Pump with moisture trap $350. If you also want the Honda GX200 engine and the 4.5 gal fuel tank, add $250. Local pick up only