You may be right on that. My 73 had an 8 3/4 when I got it, but It was already modified even before I bought it. It doesn't really matter on my car because there isn't very many original parts left on it at this point anyway[/QUOTE] Funny thing : the dealer brochures mention the 8.75" as being the diff in the 340 Duster , at least in early ( late 1972 press ) issues of '73 brochures .