This is a huge job and may be technically illegal in your state. If your state checks the emissions, it will fail after you do the swap. You would have to go through a timely re-certification process and cost you a huge amount of money. Even if you are not required to do an emission check, you need a new computer, wiring harnesses, brackets, radiator, exhaust and countless other items will also have to be replaced. If you already had the engine, it would cost you around $3,000 in extra parts, plus another $1,500-$2,000 in labor.
