I have a 2000 xj I got for free. It has a cracked 0331 head. I have a complete motor from an 89 just sitting. Im sure that has the 2686 head on it but I havent verified yet. I was going to put on a 7120 head or a 0680 head using the exhaust adaptor plate etc. my question is why can't I just the 89 non HO head? I already have it so it would save me some money. Whichever head I start with will be going to the machine shop to get checked and a valve job. Would performance suffer that much on a bone stock motor? Im just trying to get an idea of all possible directions. thanks

 

Go get the proper head.

Since you got the Jeep for free, you should have plenty of money left over to fix it right.

 

I've heard of guys modifying heads to accommodate the coil business, don't know about going BACK though. I'm 90 and would conciser getting an HO, but coming up to 300K I'll save my $ for now. Because of the cost of a valve job if I where you I might be looking down through oil fillers for that "tupy" mark at the JY. The newer heads ARE a little better.

 

Sell the used motor and take the money to fix the 2000 up right.

 

im not putting another 0331 head on it just to crack again. Thats why I got it for free in the first place. The PO put a head on it at 107,000 drove it another 70,000 miles and cracked another one so she told me to come get it, bc she was done with it. Im gonna go junkyarding this weekend and see what I can find. After I thought about it, Ill likely just find a 91-95 HO head. thanks guys

 

good idea! im going there this weekend Ill see what I can find. I might get lucky lol.

 

Just get a 0630 head and convert it to distributor or get a take your 89 motor amd put a 0630 head on that and swap motors thats what i would do

 

"im not putting another 0331 head on it just to crack again."

I didn't suggest that. Get a TUPY head or something aftermarket-wise that replaces the 0331 head and that is a direct bolt-in.

 

You can use a 91-early 99 head on your 2000 XJ, you just have to make a bracket to hold the coil packs. It has been done many times with no issues. I would not use a Renix head on your 2000. Tell me about this exhaust manifold adaptor plate you speak of, I've never heard of such a thing on a 4.0.

 

After sleeping on it, and seeing Bustedback's post, Idk. I wonder how many "revised" heads are out there. I mean in the JY. They might all be out playing in the snow! Finding one would be handy though.

""The heads that had trouble were the early #0331 heads (1999-2001WJ/TJ, 2000-2001XJ) before they were revised in late 2001 (revised heads have the "TUPY" foundry mark.) ""

 

http://www.naxja.org/forum/showthread.php?t=919384
That should be the link for the exhaust adaptor. Coil brackets are childs play to fab up. Did the tupy heads come on 04 grand cherokees? Im not gonna waste my time with the 89 head. That motor blew up anyways thats why I changed it. Thanks for the info guys! Its gonna be a tupy or a 0630 whatever I.can find at the junkyard this weekend.

 

went to the JY this weekend, the tupy motor I was after was gone. I found one in a low miles 98 that got t boned! so I looke like I will be making one good motor out of the two lol. thanks for the advice

 

Great! How much? I have no idea myself how long they put out the Tupy heads. Let us know how it goes.

 

03-04 i beleive on the tupy heads. The motor I was after was out of an 04 but someone beat me to it, i was mad! lol The one I got was $200 but I paid the yard $100 for them to pull it for me. So $300 total. I had everything with me to do it but the weather started to get a crappy so I just had them do it. Im planning on throwing in a set of rod/main bearings and possibly doing a re ring job while its on the motor stand, then putting it right in. Ill take some pics and put them up when I get around to it.