The problem with the 249 is the viscous coupling inside. Once they go it's 800 for a new one. The 242 and 231 are huge upgrades over it. Also the 231 or 242 will save you a lot more gas. My wife was commuting from phelan to Redlands at the time. She used 1/3 less gas with the 231. As Grimm said the full time 4wd is nice but if the weather is thath bad I lock the 231 in and don't go very fast anyway. Either way you go you will need to take the front Input out of the 249 and put it in either the 231 or 242. While you have the case open you might as well put in a sye and run a cv shaft. Doing the 231 with sye and cv shaft was still cheaper than replacing the 249 when I did mine. It seems like a lot but it isn't that bad. Easily doable in a day.