Craigslist, car-parts.com, etc but for the np241or the price has come up on them because all the rubicon guys who upgrade know now that tj zj and xj guys want their old stuff so the prices have crept over $1200
Yea good luck, they've been in the 1000-1500 range for quite a few years.
You can call Turn Key Engine Supply in California, they used to have them from time to time, leftover from LS swaps in jeeps.