don't be afraid of asking questions ! the only "dumb" question is the one not asked ! the 2 7/8" wide dimension gives me reason to wonder because in measuring mopar brake shoe lining for 50+ years, they have all been 2 1/2" or 3" wide. so at 2 7/8", man i don't know. and part numbers are not casting numbers. as to what someone else has on their car, anything is possible. i owned a junk yard from 1970 to 1985, and the ONLY 3" wide drums i came across was on imperials, newports [very rare] wagons with the tow package, and newyorkers. to have you order 3" replacement parts because someone claimed they were factory, i would, in all sincerity, have to have more than one person confirm those were indeed factory installed. if you could round up the necessary parts and find out the drums were 2 1/2" on your car, the backing plates, in my opinion, would really tough to come up with to complete the swap. please keep us updated on this topic. we can all learn from each other. one infamous quote is : "never say never with mopar"....