You can't. You'll need 15" - unless you can find someone selling a set from a late model TJ Sahara (2002/3 IIRC) which had 16" Alloys fitted as standard before they went back to 15" in 2004.
If you go onto the 'NP242 transfer box' thread you'll find contact details for KD. Not sure if he has steels, but he'll have XJ alloys going cheap.
