Yardsale is correct, but a 4WD explorer or 4WD ranger should have the balance shaft also, I know my 2000 explorer AWD does, but the intake and thermostat housing are different, find a good engine with a balance shaft and use your intake etc. and see if the wrecking yard will cut the price a little if you remove them and give, them back. The people I usually deal with will. But they all so let me roam the yard and pull parts myself to.. Two of them on sundays when they're closed and Im off work. I bring a six pack and they lend me they're yard dog LOL