head interchange questions/confirmations...

I couldnt find exactly what I needed in the search so Im asking here. I have a 00' xj 4.0 with a cracked head and Im contemplating options. I found this bit of info on head interchanges.

"Not directly - the intake ports are too low on the side of the head.

1991-1995 (7120) will work, 1996-1999/2000 (0630) will work. 1999/2000-2007 (0331) will work, but get that from a 2002-up WJ/WK/TJ, since it's the revised casting.

Can I assume from this that anything from 91' on up will work on a 2000? It looks like they went to a new design for the intake/exhaust manifolds in 00' from my manual it looks like they wont bolt up. Also are they any heads that are more desirable than others? Will any mods have to be made to get any of these heads to fit or is it a direct swap?

1991-2006 will work. 1991-1999 (7120 and 0630) heads are likely to require an "adapter plate" between the exhaust ports in the head and the exhaust primary tubes in the header - the ports were reduced in size for the 0331 head.

You can also source a later 0331 head - the casting was revised/improved somehow (or just a different foundry?) sometime in mid-2001, so you can check late 2001-2006 WJ and TJ. The head you'll want will have "TUPY" cast into the upper surface, inside the valve cover rails (I believe.) This will be a direct swap - smaller exhaust ports, COP/DIS bosses, and the like are all there.

The intake ports for the 7120 and 0630 head will line up, you'll just have trouble with the exhaust ports.

Ah - thought I had this link somewhere: http://www.naxja.org/forum/showthread.php?t=919384 Check it out, and you'll get a better idea of what would be involved in trying to use the earlier head...

thanks for the info. Apparently I didnt search very well. So it sounds feasible but I dont like the adapter idea. Wonder how the new castings are holding up, that route is still a gamble. So much for cheap and easy. This deal has soured me on jeeps. I dont know why I continue to buy mopars, they have all been trouble.

I think out of the 14 plus years of production in XJ's 2000 and 2001 are the only bad years for heads. Thats still pretty good odds over all.

Ive only owned one XJ, the other two mopars: 84 wagoneer and a 76 dodge aspen. Course I suppose that wagoneer was actually a jeep and not a mopar? Coulda swore it had a 360 and a 727 trans. Either way both or all three had lots of small problems that add up to one big headache for a working college student.

My XJ so far: window regulator, cracked head, blown exhaust gasket, liftgates, window and turnsignal switches, and lots of rusty broken bolts. Not to mention the regular maintenance stuff like oilpan and valve cover gaskets, thermostat, shocks, brakes, sensors, etc. This is a 00' with 135k. The up side is that I paid 5k for it which was half of what I would have paid for a similar 4runner, so I guess Im still ahead if you dont count time and labor.