I have a box with the orginal 4 piston 67 Camaro calipers and brackets in it somewhere, they were a pain in the ass, leaking every two years. I converted to 69 single piston 20 years ago and have not screwed with it since. Good to know what they bring on Ebay, someday I am going to have to figure that out.
I am interested in the Hydroboost idea for my old age. Are there pictures somewhere.