Counterfeit Carter M6866 mechanical fuel pumps being sold on Amazon. Buyer beware!
The Carter on my Dart that I kept from way back in the day, also has a "narrowed" section for added clearance to the timing chain. I bought a new M6866 way back before the slants took over everything that use to be Made in the USA. Lots of "imposters" posing as "Genuine" nowadays. Buyer Beware for sure.