My 88 Wrangler has a worn out 258 six w/5 speed. Rather than rebuild and continue with carb and emission system woes I am thinking about a later model engine. Will the 4.0 six bolt in, and what problems will I have? What year engine should I look for? What components outside the engine (computer etc) do I need to make sure are included with the engine purchase? I have the weak transmission and have some transfer case woes, so what about bolting in the entire package... engine, transmission, and transfer case? Will the driveshafts connect without modification?