8.75 SureGrip , Is this Normal?

Thanks for the info Trebor. I have the RH axle all bolted in and the LH axle seems to slide in ok (although I have not bolted it right in tight yet). What you describe, sounds like there are two concentric splines on each side. So luckily I have another 8.75 Suregrip out of a car that I can look at and yes, on each side I can see two concentric spline tubes - but whether they can rotate independent of each other (on one side), that I don't know. If one axle is all the way in, I cannot see how the other side splines could be misaligned, unless that axle was only put in part way and only accessed the outer spline section and was turned, while the inner spline stayed still. I am not sure they would rotate independent of each other. However I will check carefully when I do this. If a pry bar has to be used, does this mean that each concentric spline tube is locked in somehow to a spring mechanism? That is the part I am not sure of, but until I try it I cannot really ask more.