The bolt boes through the bracket, then the ear, then the spacer in between the ear, then a small spacer behind the ear into the head top thread. You need the single or dbl groove crank pulley, and over the big style water pump pulley. It will work with both single and double belt alternator. The alt bracket is like a triangle symbol, it will say top on it. And it should be used with a driver side outlet water pump housing and the top bolt on the bracket will bolt to it, the bottom bolt bracket hole will take a small spacer to. So you need 3 spacers, the correct upper and lower pulley and your alt. This fits the 70 system. 68,69 , 70 71 bb