Ok since I started this I just went out and took of the carb that was on the 68 Manifold with a spacer plate. (unknown what the heck it is) Both the 67and 68 side by side have Same casting numbers all 8 bores 1-11/16". The only difference I could see was the casting dates. My 625 Carter AFB comp series fit on both and carb plates opened up on manifolds.
Originally I was just wondering if there was any performance difference, but I guess we answered that now.

I do thank you for all the replies.