Hey Mike, I just go to one of the larger salvage yards...they put it out on their computer and I've been lucky so far, box, pitman arm, high pressure and return hoses, for $175-$225.00.(That includes shipping it in.) Lots of yards in Alabama, Arkansas and Mississippi are tied in with the parts system. I've found one on our local Craigslist also. I'm looking for the tiny little Toyo pump...about half the size of the Saginaw pump....the Sag pump works fine, but I want to mount it down low...probably run it off my 2nd groove on the a/c compressor.
I guess there are a bunch of folks running the GM outboard box but I just don't like it's looks or having that much twisting on the front of the frame.
Dave