Engine swaps in controlled vehicles very complicated and involve the CARB referee. Even before they sniff it, has to be visually inspected. Same make to same make, same vehicle class to same vehicle class somewhat better, engine going in has to be same vintage as vehicle or newer and retain ALL the factory emissions equipment on the donor engine. Once it's approved by the referee, it's just the every other year smog check for registration. That's just the highlights and you don't want to piss off the referee :rofl:. A Gen III in one of those old Cherokees does sound like a whole lotta fun though.