You should be aware that a dual action pump is not a substitute for manifold vacuum- - - - -it's plumbed inline between the intake manifold and the wiper motor to assist, not substitute for intake vacuum. The pump takes over and keeps the wipers running- - - -sort of- - - -when you open the throttle to pass or climb a hill, and the vacuum in the manifold virtually goes away. About the only thing you'll be able to find these days will be a 3rd. world "rebuilt" unit- - - -new ones haven't been made in a couple of decades, at least. The reason they're so scarce is a lack of rebuildable cores.
Jerry
