The differences between a hydroboost spec ps pump vs a "regular" ps pump are a slightly increased pump housing fluid capacity, a second return line hose nipple, and an ever so slightly higher GPM (gallon per minute flow rate). The pump guts are essentially the same, the the "cam profile" is optimized a tad to optimize the application...
Price a reman hydroboost spec pump with reservoir at the local auto supply house - you may be suprised how inexpensive they can be + you don't have to risk contaminating your setup with any possible gorp that may be in the used pump...
Paul
