Well... What year XJ do you have. There are two versions. A 27 spline that you'll find in the earlier '96 model year, and the previous years for the XJ. Generally, late '96es, and up to the demise of the XJ, had the 29 spline 8 1/4.
They are both pretty strong. Even thought they are a "C"- clip axle. basically meaning if you do break an axle, the whole wheel will slide off of the XJ.
Really there is so much to this question. Like;
What lift do you have? are you using a locker? what kind of wheeling do you do? what size tires are you running? or want to run etc., etc.
You can use the search feature that
provides, and believe me you will get flamed for asking a question like this without first searching. This site has an extensive amount of info on your very question.
Try using the search. If you don't find what your looking for, then ask your questions.
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