XJ 4.0 Block swap?

I have an 89 XJ with a 4.0 and i managed to throw a rod through the side of my block after sinking it to the framerails in a mud hole in my friends back yard. a friend of mine has a newer xj with a spare HO motor due to a wreck he had. will the block from his HO motor work with my non-HO head or will my intake/exhaust manifolds fit on the HO head. My friend's motor does not have a computer or wiring harness so i need to know if there is a way to make this motor/block work with my older electrical system. I have never had problems running a stock xj on rocky trails, only in the mud. I think this will teach me to leave the sloppy stuff to the big guys and stick to the trails.

The quick answer is don't bother using just the block, just swap everything over. Swap the passenger side accessories onto the HO block and use the HO Intake and exhaust. Put the Renix electronics on the HO.

Try the following link for anymore information you may need. The Search feature on boards is a very nifty tool for any specific questions you have, too. This is a very common topic and searching will yield more information than you think.

http://www.naxja.org/forum/search.php?searchid=347868

If you have to worry about smog, just switch all your manifolds and valve cover to the new motor. It will all bolt right up. You might have to switch some of the brackets. This way you don't have any computor or wiring issues, and it all looks original.

You will have a few issues to take care of- the temperature senders work differently on the HO than on the RENIX system (revers response, I think). You will need to retain your Renix temp senders to give correct information to the gauges and engine computer. The power steering pump bracket works differently on an HO engine, I don't know if your pump will just fit in, or if the belt will still be the right length, or the pulleys will line up--check first. You must have the Renix TPS, the HO one doesn't work the same way/not compatible with the Renix computer. The end of the throttle plate shaft is different on an HO throttle body; adapting the Renix TPS to it can be done by building a fitting (reported- I haven't done it yet). The posts above are correct that everything will bolt up (head, manifolds) but that still leaves these other concerns.

The above post is correct. You will have to use your knock sensor, and temp senders. you also have to use the old flexplate, flywheel, and cps. It's really easy to do if you have both motors side by side to switch everything over. the power steering worked on mine fine, yours may be different. The pulley and belt size are the same.

Here's a link for the electronics. Also look at Cherokee America for the wiring on the Radiator electronics. I do have an '88 block that I'm going to pull here soon. It has at least 144K on it. The speedo wasn't working when I bought it. I might consider a trade for your friends engine or money. I am swapping in an '03 block into mine with '95 head. But I am going with '95 wiring. Let me know if I can be of help. Im in Hope IN.
Tom

i'm surprised to see another person from hope on here. "surprising little town" is right. when i first posted this question i didn't know a whole lot about the motor. i was told that it could be anything from a 93 up, but i got back in touch with the people and they informed me that it was for sure from a 99 which is after they stopped designating the motors as HO's. will this make any difference to the above information i've been given or is it still basically the same deal

the motor is all together... i ran into a torque converter issue and still dont have my tranny back in. i turn the key tomorrow to see how it all works and if it works. i ended up using the 99 block and head and re-used the old manifolds, sensors, and water pump. the newer water pumps protrude out into the clutch fan so that had to be changed.