Hey. I recieved these two barrel Intakes as a gift. So now I'm thinking about a carburetor change on my '68 Valiant 170cui. The original carb is a Carter BBS (one barrel) I read that the best and easiest would be to put a Carter BBD (two barrel) on it. But there are some different BBD versions right? Which one exactly should I take for my '68 170cui...?