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98 versus 01

PSoffe

NAXJA Forum User
Location
So Cal
So, i have a 2001 with the now CRACKED 0331 head. As I cannot afford a stroker or even a replacement such as an ATK or Jasper motor, my thought is this. I have a local shop that parts out XJ's. Ive done business with him before and consider him very reputable. He has a '98 that has great oil pressure and compression. I want the bottom end and replace the head with the ProMaxx (formerly Alabama) for the 2001.

Knowing that the '98 has a distributor what other differences should i be aware of or should i can the whole idea.

I've been told that other than the distributor the 98 and 01 blocks are identical.

Can the distributor port be blocked off?

Is the '01 head interchangeable with the '98 block?

Trying to get up an running by Thanksgiving

Thanks
 
Any 1990-2001 XJ Cherokee or 1993-98 ZJ Grand Cherokee 4.0 L engine block will interchange. The heads interchange also but you may need to make some major exhaust changes if you use a 0630 or 7120 head. Will a head swap to a different casting number pass the CA smog inspection ?

Remove and re-use ( or replace with new ) as needed or required from your original engine: Intake/Exhaust manifolds, throttle body, flex plate/flywheel, cylinder head, water pump, distributor-less ignition pickup or distributor assembly, OBD engine computer sensors, fan belt driven accessories, and/or mounting brackets.

If your 2000-2001 XJ Cherokee has a cracked 0331 head, buy a good used redesigned and more durable TUPY 0331 head from a 2002+ 4.0L TJ Wrangler 1997-06 or WJ Grand Cherokee 1999-04.
 
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Is there something wrong with your lower end?
 
Once the 4.0L went distributor less they used a cam sensor. You'll need to swap them in. I'm not sure if the drive gear setup is the same. Otherwise I think your plan will work. Buy a head gasket set for the 2001, or at least the manifold gasket for the 2001. There really aren't any other differences for what you'll be touching other than electrical connectors, on things like the alternator and starter. The timing gear set is also different so if you do that buy it for the 1998.
 
The 2001's 0331 head has smaller exhaust ports than the 0720 head. The 0331's stock exhaust manifolds do not fully cover the 0720's exhaust port.
The cheap/poor fix is an adapter plate, the better fix is an aftermarket manifold, made for the dual mini-cats.
http://www.naxja.org/forum/showthread.php?t=919384
https://jeepexhaustadapter.com
http://www.bankspowerproducts.com/Banks-Power-51306-Torque-Tube-System-p/51306.htm

You live in SoCal, so it needs to pass the visual inspection.
Brackets will need to be made to hold the coil rail in place, the 0720 head does not have the threaded mounting holes that the 0331's coil rail uses.
http://www.naxja.org/forum/showthread.php?t=937214
 
From my short lived experience having an 01 I would suggest just getting another head from one. It's the cheapest, easiest option. Or what Tim suggested, "If your 2000-2001 XJ Cherokee has a cracked 0331 head, buy a good used redesigned and more durable TUPY 0331 head from a 2002+ 4.0L TJ Wrangler 1997-06 or WJ Grand Cherokee 1999-04." If you can find one is the best route. Yes, you can swap an earlier model head but it's a pain and not cheap.
 
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