Here's a great reference for weight reduction in A-bodies for common parts, no mention of F/R distribution change but it's pretty easy to get an idea which parts go on the front or back of the car...

A-body Mopar Weight Reduction

I haven't done much to reduce weight on my '70 Duster aside from an aluminum intake and gutting the factory A/C system from under the hood but I do plan to relocate the battery to the trunk; thinking of going with stock or slightly larger battery to maximize the offset effect. I also plan to replace the steel 15" Rallye wheels with something aluminum, probably no bigger than 17" for weight reasons (am I thinking right here? lol... tires will be 26" tall in front, 27" in back). I'm also thinking of ditching the factory power steering system and going with a manual box and electric P/S system out of a newer car; I've heard it's pretty straightforward and very cheap. I'll need the space anyway when I do my Gen 3 Hemi swap.