Working on a little project today - installing the distributor HEI adapter. I bought this adapter from the website designed2drive.com. As the website explains, this adapter (the yellow dichromate part) installs under the vacuum canister and the 4 terminal HEI mounts to the adapter. It only installs one way so The installation was pretty straightforward. I used an old plug I had along with the provided terminals and heat shrink to install the plugs on the HEI module to the electronic distributor. The other 2 HEI terminals go to the positive and negative of the coil, eliminating the ballast resistor.