I have a factory 10 bolt rear axle 8.5 ring and pinon not normal 7.5 or what ever it is

I need to buy custom axle shafts and am trying to avoid taking them out to measure them so I don't have to spend the money for gear oil twice

my first question is does the 8.5 use the same axle shaft as a 7.5 because isn't one a 30 spline (8.5) and a 28 spline 7.5

im also re gearing the rear will any 8.5 master rebuild kit would work right all the same internals as like a Silverado 1500 10 bolt for example