sell your truck, buy one with a 4.0, there are much better things to waste your time on, like drinking beer and thinking about doing something, but then not really doing anything because its easier..unless you plan to swap in a fuel injected 351w, that is something that is worth spending the time on...dont build what you can buy from the factory, build what the factory should have built in the first place!!!
*edit* this is the same as the "what do i need to do to convert my 2wd ranger to 4wd? threads" the awnser is always the same, sell your 2wd and buy a 4wd... same poop different pile..