The gap is very real but I would spot the B1G a few extra wins due to favorable matchups from the past
(SEC 2/B1G 3, 4/5, etc). And now that the SEC gets to handpick their matchups in the lower tier bowls? It's gonna take a while to reverse these stats.
EDIT: Catch 5 was right about the conference rank matchups. I'm not sure what got mixed around in my head to make me so convinced of that.