Unless you have a 305 already there, you would be better off going with a 350. Its the same size block but more power, cheaper, and easier to find. I just did this about 6 months ago, except I yanked out a 304 for the 350. You will need new motor mounts, either bolt in or weld in. A transmission adapter depending upon what tranny you have. Possibly a new radiator. I used a 350 swap kits that included a new radiator and motor mounts from 4x4 parts i believe. Since I also swapped in the Chevy tranny and T-Case I didn't need an adapter. Everything else is pretty straightforward, as long as the new motor comes with all the brackets and such.
2013 Commando Sport. Manual. Rock Krawler 2.5" X-Factor lift. 35" MT/R's, 17x9 Pacer black wheels. TeraFlex adjustable tire carrier. AEV front bumper. Warn 9.5 CTI winch. TrekArmor seat covers, Spiderweb shade
Build Thread : http://www.jeepforum.com/forum/f96/c.../#post15031329
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