Generally speaking, the larger the number, the stronger the diff. The X rear diff is generally regarded as stronger than a Dana44 (which is the most common of the medium-duty Dana series that are really worth their salt), and on-par with the Ford 9" (though we don't have the rear pinion support that makes it so famous).

Brent
_________________________

Tip: see if your question has already been answered before asking it. Try our handy-dandy search tool!