Factory BBP on 7.25 axle

Bingo.......

Found a source for it. It seems the 7 1/4 was used on A,F,M and J bodies

F-Bodies (1976 to 1980)

1976 to 1980 Dodge Aspen, Aspen R/T
1976 to 1980 Plymouth Volare, Road Runner
1979 to 1980 Plymouth Volare Duster (special Volare package and not a separate model)
Wheelbases:
108.7": All 2 door models
112.5": '76 4 door models
112.7": '77-'80 4 door models


M-Bodies (1977 to 1989)

1977 to 1989 Dodge Diplomat
1977 to 1981 Chrysler LeBaron
1977 to 1981 Plymouth Caravelle (Canada)
1982 to 1989 Plymouth Gran Fury
1982 Chrysler New Yorker
1983 Chrysler New Yorker 5th Avenue
1984 to 1989 Chrysler 5th Avenue
Wheelbases:
108.7": '80-'81 2 door models
112.7": '77-'79 2 door models; '77-'89 4-door models


J-Bodies (1980 to 1983) (All models were 2 doors with a 112.7" Wheelbase)

1980 to 1983 Dodge Mirada
1980 to 1983 Chrysler Cordoba
1981 to 1983 Imperial

Thanks everyone for you help!