Confused about open carriers?

[kevin1968s]

I have 2 different carriers.The first one came out of an older 7.5 s-10 2wd rear with GM 3.73 gears.The 2nd one I bought off e-bay that is from a newer 7.5 rear with the pear shaped opening which was told it fits 3.23 and up gears.
To my understanding they should both be 3 series open units but when I sit them side by side the gear mounting flanges are not at the same height.
Could one of them actually be a 2 series unit?
Can any one shed some light on this?

[HAM1974]

if it came out of 7.625 i think the axles are diffrent the older s10 had 26 splines, the newer 28 splines. i think the later was 88 and newer!

[kevin1968s]

Actually the newer is a 28 spline carrier which I guess is the 7.625
Will these carriers fit into the older 7.5 rears?

[kevin1968s]

I think I figured it out.The 28 spline carrier that I have is only a 2 series carrier.
And the 26 spline carrier is a 3 series.