If you're thinking of doing lockers or a limited slip diff, your best shot at doing it is while you're swapping gears.
Whether or not you need them is up to you- if you're wheeling, you'll want a limited slip rear. Not a huge investment ($3-500), and pays dividends on and off-road. Going by your desire for 4.56's, you're looking more at fuel economy, so probably not wheeling. If so, you probably should just rock the stock open diffs, nd let the BDS system do its thing- Mark W.
A forum community dedicated to Jeep Wrangler owners and enthusiasts. Come join the discussion about reviews, performance, trail riding, gear, suspension, tires, classifieds, troubleshooting, maintenance, for all JL, JT, JK, TJ, YJ, and CJ models!