Spring plate bushing binding or ?

[klm2500hd]

Backstory, I replaced the suspension bushings on my 84, ride height settled in at 1" lower than stock, now the rear feels very bouncy. Could it be the Weltmeister poly bushings are binding, Koni yellows need to be adjusted, or something else? Any thoughts? I plan on reindexing to get ride height back to stock, ride is firm which is good, but really bouncy, especially at lower speed.