Ive decided to replace the 4.7 in my 00 grand cherokee. it has a rod knock. how hard is this gonna be? should i just replce the crank and bearings or the whole motor? I can probally do either, just thought the crank kit will fix my prob. it has 180,000 on it. any advice would be greately appreciated and ill post pics!! Help me! first time engine removal and overhaul ever!