Good news folks! My last shot in the dark ended up being a bullseye, I ordered a 74 Dart booster just by chance and it's the correct one complete with the space I will install tomorrow! Thanks for all the help!

One last thing in the spacer I seem to remember there being some sponge material between the plastic piece and aluminum piece. Does anyone know if that material is required, because my new one didn't come with any... Maybe I need to cut my own? If so does anyone know what material it is?

Thanks again!