8 3/4 vs 8 1/4 weight

I’ve been reading FABO and getting plenty of opinions, but very few actual numbers, so...
Does anybody know the weight difference between a complete 8 3/4 rear with Mopar disc conversion and an 8 1/4 with drums setup?
Both are A body, all stock Mopar parts and big bolt.
It sounds like a big splitting hair problem... My first question would be what does it matter? I can't imagine it being that big of a difference... Unless it's some very special race specific application you're needing and even then...