bolt in sub frame connectors

Hi, I have a 67 Barracuda. I am looking at buying a set of bolt in frame connectors. I have seen only one set that are weld in but they don't list they will fit a 67. They list they are 68 and up. Does anyone know if the underside of the cars are different from a 67 to a 68 and up? Also does anyone know of a company that makes bolt in connectors for my 67? Thank you

Robert