I know everyone has their ideas about swapping out their engine for a low-mileage used unit. For what its worth, my indy mechanic, who I really trust, said he would never recommend doing a swap with a used motor, too much of a gamble for him, especially when you take into account how much the labor costs with the swap. He said he has seen a number of times where the used motor in the swap developed problems a short time after the swap. For me, the peace of mind going with a rebuilt motor would be worth the price of admission. But where I would come up with the funds for a rebuilt.........
Ed