Positive and negative battery cable sets 67, 68, 69 A body SBM

dibbons to answer your question, 67-69 A body use a single wire negative cable, and have an engine to firewall ground wire. 70-72 negative battery cables have an extra 12 gage negative to body ground at the radiator support with a 1/4" ring terminal. This additional ground wire I believe is 14" long. I am going to work on doing those next. Some of my parts I ordered are on back order currently. Positive for SBM in an A body are the same from 67-72. I think the auto parts store negative cable is a generic kind of a deal, so it has that extra ground lead to be used if needed or just clip it off. It would not hurt to add in a battery to body ground on an earlier than 1970 car.