spline

Hey you gear heads; I've got a 2010 XLT 4WD, payload package 2. I'm thinking about putting a Detroit in the 8.8 soon. I read on some Jeep 8.8 swap site that a 28 spline has 2.75".OD tubes and a 31 spline has 3.25" tubes and necks down at the brakes. I just went and measured the tube OD; it's...