I've done this swap I put a 95 HO 5speed drivetrain into my 88 5speed. Are both cherokees 5-speed? If they are then DO IT, Its easy. Go to cnyjeep.org and register and lookup my writeup for the tranny swap writeup i did im cherokeenut on there. Second the HO 4.0L will swap right in. Use your intake and all your sensors and put them on the HO motor and just use the HO exhaust manifold as its a better design. To you guys that say its not possible it is think about it, the motor has the same displacement, Same stroke and bore, and the same timing. The only differences is the Head design as the exhaust and intake ports have been played with to make it a HO and 95 and newer HO have been changed a little here and there for Emissions. That and the output shaft has more teeth on the newer HO. So bolting an older tranny to the HO gets tricky. And putting the newer tranny in an 88 would require the computer to be swapped from the donor to the 88. But if they are both 5 speed then put your intake from ur RENIX injected 88 right on the HO with the 88's sensors, then put the rest of the 88's sensors in the HO block at their appropriate places. You will have to shave the corners of your RENIX intake to fit the newer style exhaust manifold below the Intake but its easy and you only have to shave maybe 3/16's of an inch off the outer lower corners of the intake. In fact the RENIX is a very good computer but it doesn't store codes that's its one downfall. It does however have a knock sensor which no HO chrysler fuel injected 4.0L did. The knock sensor allows the computer to "hear" (if u will) pre-detonation of fuel and change the air fuel mix to stop it so the engine doesn't get damaged. I would say use the newer tranny and t-case too as swapping the old to the new motor is the hard part. Put the whole 97 setup in your 88 its easy the bodies haven't changed over the years. The RENIX computer is popular for stroker motors as it comes with a knock sensor and all its sensors are easily connected to the APEXI SAFC II and other programmers for fuel/air tuning. You will have to use all ur brackets and accesories such as alternator powersteering pump and a/c on the HO motor but it all just unbolts and the non HO stuff bolts right on i did it in my garage in 2 days. All the sensors swap with the intake and the oil filter housing (and pressur sending unit) swaps right over from the non HO to the HO its just vertical instead of facing the back. And the distributor drops right into the HO block from the Non HO block. Swapping the intake fixes ur fuel pressure and injector nonsense. The only thing you guys didn't mention was that the flywheel or flexplate is different depending on whether you have a 5 speed or an automatic. The timing teeth on the flywheels (flexplates if automatic) are different for the different injection system. If you swap the flywheel from your 88 onto you 97 it will bolt right on and the clutch assembly will bolt right back over it. Note however that i swapped a 95 drivetrain with a 5 speed into my 88 that was a 5 speed. If u have an automatic 97 u will need the computer from the 97 to control the tranny once you put it in your 88. So if you are swapping a 5 speed drivetrain into your 5 speed 88 there isn't much that needs to be done other than changing the flywheel and all the engine accessories. If your 88 is an automatic and you want to put a 97 5speed drivetrain in it then you will need to install the master cylinder and clutch pedal from the 97 to the 88 then bypass your neutral safety switch for your 88 so it will still start with the 5 speed drivetrain. Bolting the tranny from the 88 to the HO or bolting the newer auto into an 88 is where things get tricky because the input and output shafts change from some years and the newer tranny has a computer that it needs. Thats why I stick with the 5 speeds. IT CAN BE DONE IF YOU WANT IT TO GET DONE

I figured no one wanted to give you the details so thats most of the details sign-up for cnyjeep.org and private message me if you want some help with it or any further details i dont mind looking stuff up for you to help you out.

The non disconnect front end is better its got a solid passenger side shaft and the 231J is the tranfer case that 97 has if it has the option for 2hi. Its a better case for offroad use but you CAN'T use 4 wheel drive unless on slippery surfaces or you will destroy the transfercase. Actually the front axle is better too from the 97 as it has larger u-joints and it will swap right in no changes to the design from 88 to 97 as far as mounting or driveline changes just the u-joints and it not having a disconnect. The rear end will swap right into your 88 too if it was setup under the 97. So i say get it just to get the 8.8 all setup for your xj and to get the larger front u joints and get rid of your vacuum disconnect. The 8.8 is arguably as strong or stronger than a D44 which your xj might just have under the rear end of it. The D44 was offered from 87 though 89 i believe as part of a tow package on the XJ. Look under your jeep and remember the shape of the Rear Diff cover and take a look online you have the Dana 35 (piece of junk - mine did last 250K miles but its hit or miss with this axle) or else the D44 under your jeep. Look it up if you got a 44 under that XJ your lucky.

And the HO was the only 4.0L jeep used in a cherokee after 91. So the 97 is a HO whether it says it on the hatch or not.

And all the D30 front axles from 88 to 99 in the XJ's were High Pinion reverse cut. Low pinion standard cut was 00-01 and was in all YJ's and TJ's(I believe). Im not sure about ZJ's I believe they were high pinion standard cut though. A low pinion in the front drives on the coast or beveled side of the gear and under higher loads, the pinion teeth are forced out of the contact area into the higher thinner edges of the teeth and that's what tends to destroy the gear teeth. A high pinion on the other hand drives on the flat side (drive side)of the tooth and the contact pattern tends to remain static regardless of the loads placed on it. Low pinion is Stronger in reverse if thats what you need?. Oh and standard cut is worse than reverse cut for front axles and stronger for a rear end gear (look it up). You have the strongest D30 Jeep offered under the front of that 97 XJ.