Just what precisely is the requirement for engine swaps? I have this 91 I4 Ranger in the yard and my 87 F truck with a V8 and another 302 block in the basement. The iron in the basement is out of a 68 Fairlane (I think Lenny posted a question about it somewhere) via a Mustang. The F truck is looking down the barrel of a loaded rebuild and the old lady says the Ranger either gets fixed or it has to go.

DMV took their time about answering my question and eventually sent me an EPA form letter saying the federal gov't requires same year or newer.

So. Do I need a 91 or newer mill or can I build the iron in the basement?