abdo

I just bought the rectangular exhaust tips that are use on later C4s. I am putting them on my '86 coupe. Included in the package were 4 steel sleeves about 1/14 inch wide and the diameter of the outlets that I assume fit on the muffler outlets. There were no instructions with the kit. Are these necessary? If so, where on the outlets do they go? Do they provide the necessary thickness so that the adjusting bolt secures the tips better?
I know, dumb questions, but I'm curious.