rear disk conversion

[CJJ67]

This is my first post, but i've managed to keep my truck running thanks to the experts on this board. I converted my 67 to front disk brakes but my question is what about the rear? I read somewhere that you can use the stock brackets from a 77-79 cady deville. Can I use the stock brackets from a 79-81 eldorado. These type cars I can find. If not, what other type vehicle should I try. I really want to thank all the experts who freely share their knowledge. My wife thinks I'm a genius.