The very last year for the Plymouth 4 door hardtop was 1976.
1974 was the last year for the Fury I, Fury II and Fury III. They were replaced for 1975 by the Gran Fury Special, Gran Fury, and Gran Fury Custom. The top line was the Gran Fury Brougham. Both the Custom and Brougham had a 4 door hardtop. For 1976 both 4 door hardtop models were gone.
Have always liked the 4 door hardtops more than the sedans. The Plymouth and Dodge 4 door hardtops usually appeared more sporty than the Chrysler and Imperial models, which were more formal.