Having done a few of these, it just really depends on what you are really after. If you're a purist, be pure. If not, go for what you want. Just to provide you a left turn on what you're trying to do, my next project will be an FJ60 on an FZJ80 frame with a tuned Duramax 2.8 liter 6-speed auto. The trucks that these combos came in are actually a little bit heavier than an FJ60, so I should be good. My goal is to have a fuel-efficient daily driver. So figure out your goal, plan it all out, and then go for it! It doesn't need to happen all at once.