What can a 7 1/4 rear take???

You can put any 7 1/4 gear in a 7 1/4 rear, and yes there is a 3.23 ring gear. If you are asking what I think you are asking gears are not interchangeable unless they are from the same size rear end, meaning an 8 1/4 ring gear is not comparable with a 7 1/4.