Narrow track axles usually have better lower gears, and the front dana 30 has 6 bolt lockout hubs which are much stronger than the later widetrack five bolt lockouts. They both still have 5x5.5 flanges for the tires. So yes, they are stonger, somewhat.
If you aren't afraid to get dirty, I would swap everything over from the narrows to the wides... best overall axles.