Where to find Ford 9"?

[mattausten23]

I want a better rear end for my 67 camaro so that I can build my 3 link! I know I can get 12 bolts all day from the junk yard but I see people running Ford 9s. I was just wondering why are Ford 9in rears used more? Are they a lot better? Also would it even be a good idea to pull one from the junk yard and re build myself to keep the $$$ down? Thanks for the help!
Matt