Well the things they did get wrong were what Andy touched on were items that would have saved them Millions in development and production costs. The left hand lug nuts were a good idea as Rolls Royce also used them.
One common distributor for all V8's would be a smart move like GM did. Ford was even worse than Chrysler for some of these items and it seems that Chevy was the only ones that were smart about production costs twocents
The wheel wells on the rear not being bigger was my biggest problem like on my old 66 Belvedere sawzall hammer

Gus beer

64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60