I mentioned earlier that there were 2 versions of the bracket from the compressor to the intake manifold. This High Performance Pontiac Article compares different intake manifolds. Photo 11 shows the 2 brackets together. Starting in 73, the front mounting boss on the intake manifold was moved outward and the front arm of the bracket was shortened. If you are using a later intake or an aftermarket intake, you might need the later upper bracket.

Here are some pictures of an early style bracket. The first one shows the bracket next to a 67 intake manifold. The bracket holes align with the bosses. The second picture shows the bracket next to a Edelbrock Performer intake. You can see the front mounting boss has been moved toward the edge of the manifold.

Pete

Early bracket and 67 intake


Early bracket and Edelbrock Performer intake