If you're looking for means of making your axles stronger, then you might want to consider the EVO Manufacturing 44 Magnum Sealed Sleeves. The name itself has authority. After having these installed, expect to have an axle strength increase by as much as 30%, and the dual seals will keep any road or trail debris from getting inside the axle tubes.
This combination will ensure for extra longevity out of your axles. These will work with all JK axles which include both the Dana 30, and Dana 44, and is a greasable design. Please note that installation requires welding, so please have an experienced welder, or fabrication specialist perform this job.