My daughter has a 2003 supercharged Xterra with 170,000 miles. Rear main seal was leaking and she ran it out of oil, oops. She babied it along for a couple of months, but it spun a rod bearing. Now I am deciding weather to rebuild the engine or replace with a used engine. A couple of questions, is the naturally aspirated engine the same as the supercharged engine, able to swap intake manifold and install supercharger? Also, how many miles will these engines run if taken care of properly?