So here u go… my jeep had low oil pressure once hot at idle, milky vaseline substance on the head and oil cap and ate through coolant. The culprit 0331 head on my jeep cracked almost directly under the oil cap which is the week spot on the head casting. The fix, pulled the head and replaced it with one from clearwater cylinder-head only issue doesn't come with the alignment pins for the intake manifold (used a permanent marker to align) also new lifters. Be sure to vac out all accessible area to get the sludge out. Pulled the oil pan and oil pump, new gasket and cleaned the pump it worked fine before so why replace. Reassembled started still low oil pressure so I did some more research and found the fix. Remove your oil sending unit and the elbow that comes off the housing take some brake cleaner and compressed air (I sprayed the cleaner down in the sending unit and it covered me in nasty crap) did it a few times until completely clean reassembled and started the jeep, at first te oil pressure acted funny most likely to air being caught in the sending unit. After a day or so of driving I haven't had a low oil light at all once hot at idle. If u got any questions just ask.

 

do you have brown **** coating the underside of your radiator cap?
does your oil look like coffee?

then you head is cracked

pull off the valve cover and look between rocker head 5/6 back to front ( i think)
the crack will be revealed by a brown line, made by rust, it should be very flat on the top of this line and should smudge downwards, indicating that the liquid flows downwards. thats what my cracked looked like.

i bought the new casted head from o'reillys and it seems to work fine. and if your oil pressure sucks then yes, your bearings are screwed. Although my bearings were gone before my head cracked so i didn't see anything difference in that regard...

the oreilly website says they have a crank rebuild kit. i would consider getting that after checking your rod journals and confirming that they are dead

also my valve cover was coated with a substance that looked like cheese after my head cracked.

and if you do remove the head, remember to take the rocker heads off very carefully, they bend very easily