Being a longer wheelbase, I would have thought the Coronet shaft is longer than the Belvedere.
X2 the spring hangers are supposed to be shorter in the front on a Plymouth.
56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d
