How New Can I go?

Need a new engine for the '89 Comanche. How new an engine can I get? I know I'll have to use my flywheel, distributor and install a knock sensor. There may be a few other things also but is there a cut-off year beyond which too many things changed to make it a feasable swap?

Can I use a '99? An '01? The newer I can go, the fewer the miles on it.

Thanks for any info you can give.

You can use a late model block if you want (even if it wan't in a cherokee I believe). The sensor (knock) hole should be there but it wasn't machined so you will need to tap threads. Aside from what you mentioned you will need manifolds from the HO motor and I belive a P/s bracket needs to be dealt with.

You can also get a low-mile "shortblock" which is just the lower block components then place the non-HO heads on top after taking them to a machine shop, it should all fit fine, aside from that knock sensor.

Keep in mind, some of the later heads have cracking issues.

There is a thread here from a few days ago that gave me a lot of information, and there is an article on "Cherokee America" that tells about swapping a non-HO to a HO engine. I think someone here mentioned what years were 'cutoff years' for certain sensors/computers/etc.

I am swapping an 89 to a 93 HO engine, and have had to swap a lot of the sensors over, and am currently trying to figure out how to 'rig-up' the Throttle Position Sensor since I haven't found all the info yet and also (the what I believe is) the knock sensor people are mentioning above. I believe the threads are there for the knock sensor in the block, I just need a special tool to remove the plug that is currently in its spot. Everything else - just replace all the newer sensors with the sensors on your original jeep, but you'll need the newer fuel lines, throttle cable, and tranny cable that connects to the throttle. Other than that I believe everything hooked up fine. You also have to switch over the new engine to your old AC & bracket, Alt & bracket, distributor, coil. I have not dropped my engine to try to start it yet, so you'll have to look around for the rest of the info.

Here's where I got my info:
http://www.naxja.org/forum/showthread.php?t=64020

Hmm, what other sensors are there besides the one in the distributor... Oh yeah coolant temp, I think that has a different type sensor on later models and the sensors on the manifold itself. I thought it was possible to swap the entire (old) thottle body thereby preserving those pieces intact, if you choose to use a newer head and manifolds. There shouldn't be a transmission cable, its stick since you mentioned having a flywheel right?

I swapped over every little sensor I could find, I just unbolted the new ones and bolted the old ones in their places. It looked like they were about all in similar locations, so I believe everything should work fine since I'm using the old computer/wiring harness. I haven't figured out 100% what I will do about the coolant temp sensor that controls the fan, but I was thinking I could just extend/splice into the one in the t-stat housing and work from there.

Wow! Fast info! Thanks guys.

Looks like the best way to go for me is to simply get a non-HO engine. I don't know how long I intend to keep this truck. I would prefer a 4 wheeldrive Cherokee (my Comanche is 2 wheeldrive) and plan get one soon. So, with that in mind, a non-HO is my best choice.

All the changes between Renix engines and HOs make this a complicated swap and I don't think I should invest the time or money neccessary when I may well be selling the truck soon.

Thanks again guys. Big help here.