XJ Knight

Just wondering if anyone can tell me what years 4.0 cylinder heads are interchangeable with my 2001.

Also wondering if my head is cracked (not sure yet. Might just be warped), can I replace it with another head and not have to take the head I get to a machine shop? I guess this would also apply to if my head is warped it would be cheaper to just get another head than take it to the machine shop. Of course that only being if I don't have to take the head I would pick up to the shop..

tablerockfshr

http://www.jeepsunlimited.com/forums...d.php?t=391831
Read all about it here

XJ Knight

Awesome. Thanks

98 JeepJeep

you can use a -630 or a 7120 head......any head you get should at a very least be sent off to be magnaflexued,deck checked and valve condition checked.

5-90

If you use a #0331 head, get one from a 2002-up WJ/WK/TJ. The casting was revised slightly to correct the cracking issue (which, I presume, is why you're asking the question.)

The 7120 (1991-1995) and 0630 (1996-1999) heads will work, but you'll have to fab brackets to support the coil rail.

EDIT - Oh, and the exhaust ports on the earlier heads are slightly larger, so you'll need a "reducing plate" as well.

XJ Knight

OK just to double check my thought process here. For my 2001 XJ the best bet is a 02-06 head. The cracking issue is said to be solved and they are fit for the coil rail..

5-90

Correct. The #0331 casting was used 1999-2007, but the 2002-2007 castings are prefereable because the cracking issue has been resolved. Externally, all heads are identical by casting number - so you're not going to run into any trouble using the later head.

If you want to verify casting number when you go look for one, you'll find the number on the driver's (manifold) side of the cylinder head above the #3 and #4 exhaust ports - it's a three- or four-digit number (so you're looking for 0331 or 331.) The number is outside the valve cover, so it's visible whether the valve cover is in place or not.

XJ Knight

Thank You, Thank You, and Thank You

petesxj

i have a 2000 and ithe number is 068 am i looking in the wrong spot, its the only number on the head next to the valve cover. Its at the #3 and 4 exh port

5-90

Correct, the casting number is above and between the #3 and #4 cylinder (centre) exhaust ports, and should be outside the valve cover mating rail.

The "068" may be an "063" covered with crud - a bit of cleaning might be in order...

MVDCXJ

Did all 2000+ XJ's come with the 0331 head? Just curious

petesxj

mines a 0331 i was lookin to far back on the head, but now im curious if the other number is maybe a batch number

98 JeepJeep

that i know off....