The 304 is a pretty bullet proof motor if its been treated half way descent. The KID has her CJ, she pretty much rebuilt from the ground up while her hubby was deployed over the last 20 years, and it has the 4 cylinder Iron Duke it aint fast but it runs OK. Dad had a AMC Matador 304 2 bbl, automatic , it had over 150K on it before sis put another 60K on it. Remember you cannot drift a CJ, well maybe once. If you do go with it, and need parts the KID has the number of a JEEP recycle yard in N. Ca the only place she could find some of the parts for her CJ, let me know and I ll get the information for the place for you. One thing you need to remember AMC was going tits up and sourced parts from a lot of different places, so a jeep part might be from a ford or chevy or mopar, and sometimes parts can be found off other critters