Just caught the tail end of this topic but thought that you all might be interested to know that NAPA auto parts stocks the 'Hydrovac' units for Chevrolet trucks. I just received a reconditioned unit for my 1955 3/4 ton. Ordered it online (www.napaonline.com). Paid about $200. Seems like a good deal to get the unit from a company that provides a limited warranty and has a fairly good reputation.