Yep, put your attention toward the 258, it is a good engine and responds well to a bit of massaging. In addition, re-gearing your axles, and paying close attention to tire size. Unless you are going to go mud racing or extreme "jeeping", the v-8 will only cost you copious amounts of money and exasperation. Study up on the stuff I mentioned, and Jeeps in general; there is so much info availale it will stagger you - google is your friend, here.