Stock weight distribution for various body styles - can you improve balance w/out drastic mods?

Great thread I've always wanted some concrete info on this. It seems like the Duster/Demon/Dart Sport body generally has better weight distribution than the A-body Barracudas? Visually the Duster body seems to have quite a bit more rear overhang than the 'Cuda.

Also I thought the "square-roof" cars were heavier overall than comparable fastback models, like 2-door Valiant vs. Duster