what size motor?
Depends on who performs the repair and if the head needs resurfacing or replacing. Get estimates from trusted mechanics.
yes
possibly blown head gasket
Change it
YesYes
There could be several things that will make your 2005 Grand Cherokee Limited overheat even if you just changed your radiator. There may be a head gasket blown.
maybe you need a new head gasket?
replace the head gasket
there is no reason to pull the head to get at the oil pump.
The 2002 Jeep Grand-Cherokee has 39.5 in. of front head room.
The 2008 Jeep Grand-Cherokee has 39.3 in. of rear head room.
The 2013 Jeep Grand-Cherokee has 39.9 in. of front head room.