Keep 89 Renix, or swap to 94 HO engine?

[jakesmog]

I have a 89 Eliminator I’ve been preparing to swap to 4x4 for a while.

I got my hands on a 94 4x4 XJ, with AX15/231 and a D35. I’ve been wheeling that for a while cause it came with super swampers and winch bumpers and stuff. 
Once I find a good C8.25, I’ll be swapping the drivetrain over to the Comanche, gears and lockers etc.

 

Long down the road after everything’s dialed, I wanted to go 4.6/4.7 stroker, but still run stock heads and cam and run 87, cause really all I want is the low end torque and don’t care about top end power.

Does it make sense to try to keep the Renix, or should I just carry the HO over? Does it make sense to use the Renix intake to keep the low rpm torque, or is the difference too small to sweat? Afaik tuning the HO is gonna make that a lot simpler. Also I think there’s more adapter type stuff necessary to plug my Renix into the AX15 that came on the HO. 

 

Both motors seem equally healthy. Just trying to form my long term build vision before I start spending money and time on things I might regret.

 

Additionally I plan on running 33x10.5ish tires, 4.56 gears, 3.5” lift, and I’ve got Core 4x4 Long Arms. Trying to strike the balance between, tolerable on the highway, repairable in a Autozone parking lot, but plenty of capability off road.

[89 MJ]

Just to clarify, you are talking about just swapping the engine, correct? Or are you talking about swapping all of the wiring too?

 

Personally, I wouldn't bother with swapping the engine if they are equally healthy. I would keep that 94 engine to build the stroker out of though, that way you can have the engine built and then just swap it in when its ready. In terms of intake, I don't think you'd actually notice a difference on a stock engine.

 

If I recall correctly, you just need to find the correct pilot bushing to mount the AX-15 to the 89 engine.

 

Depending on the type of wheeling that you want to do, 33s, 4.56s, and long arms might be overkill. Since you have the long arms, I'd stick with those, but it takes a lot more work to clear 33s than it does 31s and you only get an extra inch of ground clearance. Plus, most of what I have heard says that you need at least a 4.5" lift to clear 33s without cutting. I would look at 31s and 4.10s. 

[jakesmog]

Well my MJ is going to be almost completely apart, all the axles transmission and suspension out. I'll be going over everything, it needs new hard brake lines and a floor pan, I'll be rust treating and painting everything inside and out, so to swap the wiring is not really much more on my plate.

And I do plan on trimming the hell out of the fenders, also staying SUA. I was originally thinking 4.88 or 5.13 gears but I'd rather have the stronger pinion of the 4.56.

[ghetdjc320]

I’d keep things renix. The HO doesn’t have much in the way of support for stroker builds. The OBD1 ecu which is and SBEC2 unit, can be chipped and programmed but only by a select few people. The renix system with its knock sensor has proven itself in basic mild strokers. If your after tuning performance and flexibility, aftermarket efi is you’re best bet though later model obd2 systems have a bit more tune ability and can use HP Tuners. Still not the same as a true stand alone efi system though. Strokers and custom efi for the 4.0 get you in the realm of engine swap territory 

 

 

As for the AX15 tranny, on internal slave models (pre 94), they had a 5/8 pilot tip. 94+ are 3/4 pilot tip. No appreciable difference strength wise but you may need to swap pilot bushings as mentioned. 
 

You can trim up using the DPG method with decent results and probably clear 33’s. The trick is to be able to fully stuff them and keep your turning radius.