Weight gain for Dusters/Demon/Dart Sport from 1972 to 1973?

Waay back, before I found my Dart Sport, I test drove a '71 Demon that I ended up passing on due to some body work needs that I wasnt up to...

...but the Demon drove well and looked great. The thing that struck me when I eventually found the '73 Dart Sport was how how much more "stuff" had been added. Much bigger bumpers, bigger brakes, more substantial head liner/carpets/interior door panels... Possibly more sound deadening. Granted, some of these things may be related to the option levels of the cars I drove....but there seemed to be some big differences.

I loved them both but the Sport was the nicer specimen.

So did these A Bodies gain any significant amount of weight with the changes (assuming a cars with the same engines/trans options)?