So my ex girlfriends 2001 Cherokee is having issues. Im pretty sure the head finally went in it. Im looking into replacing it with this

http://cylinder-heads.com/details.cfm?itemid=1828

Now if no antifreeze has gotten into the oil will It be fine to just replace the head? If it has can I also just replace the bearings on it with

http://www.perfectengine.com/Jeep_4_...h-rmj242ep.htm

 

She has also told me that the Oil has mixed in with the Antifreeze but not the Antifreeze in the oil. Can this cause issues?