For future reference, here is the part number history for the chrome slant six valve covers from old Direct Connection and Mopar Performance catalogs.
P3690742 fits 1960 - 1980. First appeared in the 1975 catalog and continued thru 1994.
P4120930 fits 1981 - 1987. First appeared in the 1982 catalog and continued thru 1989.
In 1990 Chrysler superseded P4120930 to P4529063 which last appeared in the 1997 catalog.