Buying blown up 2000 XJ, have 1990 4.0, will it work?

I'm buying a 2000 Cherokee with a badly overheated engine, presumably due to a cracked 0331 head and low coolant. I don't have the Jeep yet, and I'm trying to make sure I don't get myself in too deep financially.

-I have a complete 1990 Comanche 4.0 engine with very low miles

-I have a good 0721 head and exhaust manifold from 1994 Cherokee, and I'm aware of the extra cats on the 2000 setup.

-I know that I need to make coil pack mounts as the head will be different, and that I need to use all sensors and accessories from the 2000 to work with the OBDII computer.

My main questions:
-As long as I use the 2000 intake manifold and PS bracket, will the accessory belt setup work?
-I assume I will be swapping flywheels, as long as the crank will accept it.
-I will drop the cam sensor from the 2000 into the distributor hole in the 90, as long as this will work.

I've read a lot about this and I'm looking for some reassurance that this will work. I've got the time and ability to do all of this, just not much extra money if I run into incompatibility issues.
Thanks

pretty much only the block and rotating assembly is the same. youll need the timing cover, oild filter adapter and the other accouterments off the 2000 block.

Thanks for that info. I hadn't heard that the timing cover must be swapped. As long as I can swap all the bolt on things from the 2000 block over to the 90 block I'll be happy.

Why would he need to change the timing cover? The cam style changed in '98 to the newer version, but he's talking about a direct drop in. Block would be already assembled.

I'm pretty sure the only mixup you are going to have a problem with will be the exhaust port size/shape on the head vs the ports on the headers. There is a way to make it work but I am constantly forgetting it.

Also, check Talyn's thread on using a Dodge Viper coil pack to replace the stock 00-01 coil rail. It solves both the mounting stud problem and the annoyance of having a coil rail that can't be removed from one plug at a time for debugging.

DanMan2k06 said:

Why would he need to change the timing cover? The cam style changed in '98 to the newer version, but he's talking about a direct drop in. Block would be already assembled.

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The renix one would work except the belts are run differently. thus, the 2000 geometry would allow the surp belt to contact the timing mark lip on the renix timing cover. you could cut it off i spose, but the right way is to just retain your 2000 cover.

I'm pretty sure the only mixup you are going to have a problem with will be the exhaust port size/shape on the head vs the ports on the headers. There is a way to make it work but I am constantly forgetting it.

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they are a different shape, but it will bolt together just fine. the ports on the 2000 intake/exhaust manifold are slightly smaller. But it will bolt together and run just fine, without dropping gaskets.

People put the '99-up manifolds on older HO's all the time. I myself have done at least 4, and have several late model manifolds currently on the shelf for more swaps.

It's really good to hear this information from someone who has done this swap.
I had actually planned to use the exhaust from the 94 and fool the O2 sensors for the pre-cats. If I can use the proper exhaust for the Jeep and leave the pre-cats alone that would be even better.
Is there an advantage to taking down a bit of material from the header where it meets the head to smooth out the flow? I had also read what kastein said about the exhaust ports on the 7120(94 HO head) not matching up to the 2000 exhaust header.
I've got to say, the technical info on this forum blows away every other jeep forum out there, thanks for the help. I should be going to pick up the 2000 tomorrow, since it looks like I've got everything I need for the swap to work.

it certainly wouldnt hurt to match the,ports, but you arent going to notice a tangable performance increase.

edit, misread the post lol

Note: You need to have the intake/exhaust gasket for the 2000. Not sure why I got the gasket to match the head with bigger ports, but just thought I'd try to save someone else from making my mistake.

As long as I'm here...The swap does work, and I've learned a few things.

-I found that the cams are different, so you can't swap cams or timing sets.
-Just because a donor engine supposedly only has 90k on it doesn't mean you shouldn't freshen up the bottom end. I think I'll be rebuilding an engine properly in the next year to put in, if not sooner.
-Everything off the 2000 block will bolt up to the 1990 block, of course the HO head bolts to the 90 block.
-I hate the people that decided to use t55 bolts for the motor mounts on the older engines.
-My jeep is a federal emissions jeep, so no pre-cats.
-Bolting later manifolds on earlier heads does work, though it's definitely not a smooth path for airflow.

If anybody ever has the hair-brained idea to do this swap, PM me with any questions.

kastein said:

Also, check Talyn's thread on using a Dodge Viper coil pack to replace the stock 00-01 coil rail. It solves both the mounting stud problem and the annoyance of having a coil rail that can't be removed from one plug at a time for debugging.

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Oh? Never heard of that one before...i'll have to give it a read. That's been one of my main pet peeves with the 00-01 years...how they set up the ignition. How much time/money/other BS did they really save by doing it how they did instead of individual coil over?

Moneypit_k5, do you remember drilling out one tapped hole in the block for the timing cover? There are two bolts from the 2000 that go through the timing cover, block and alternator bracket. On the older block, only one of these holes allows the bolt to pass through, the other is threaded. I am thinking I'll just drill out the threads, but I would like to have some encouragement before I do something that can't be undone. Thanks!