99 4.0 out of a cherokee

Price?

Have pics of motor

The head still intact? I know they're prone to cracking

Quote from jeepin1979er

The head still intact? I know they're prone to cracking

http://www.jeepsunlimited.com/…31-cylinder-head-castings

Looks like they were a small batch of bad castings... Bad ones were 0331 heads. 7160s are ok . The 0331 head appeared on '00-'06 models though some '99's may also have it.

The head cracking issue seems to be the result of several bad castings and I can only speculate that the cast iron used in one large batch made around the year 2000 must have been of poor quality.
The area between the no.3 and 4 exhaust ports is the hottest part of the head and is subjected to the largest temperature fluctuations, making that the area most prone to crack.
The first sign of a problem is unexplained loss of coolant. If there are no external coolant leaks, remove the oil filler cap and look between the valve springs of the no.3 and 4 cylinders. A crack is usually too small to be seen with the naked eye but you WILL see crusts of coolant in that area and that's a telltale sign.
If the crack is between an intake port and the water jacket (or between the combustion chamber and water jacket), the engine might run like it's on 5 cylinders. Check the plugs and if one of them has less carbon than the others with traces of coolant, you'll know which cylinder is affected.
If it's between an exhaust port and the water jacket, you'll have steam coming from the exhaust but the engine will run fine.
If the crack is only between the water jacket and the crankcase, you'll only have the mystery loss of coolant with the engine otherwise running well.
Left neglected, enough coolant can accumulate in the crankcase to contaminate the oil and result in accelerated main/rod/cam bearing wear, manifesting as low oil pressure.