My wife bought us a 89 YJ with a 4.2L manual transmission. It has been lifted some and currently has 31s on it. I've been doing some research in regards to axle swaps and possible stroking the 4.2L. Any suggestions in these areas? As far as axles go I am thinking about dana 44s in front and rear. What would be a good donor vehicle to get these axles from? Any opinions on stroking the 4.2L? Of the two projects, where would you recommend we start?
Congrats on the Jeep. I have 2 older YJ's also. Are you planning on bigger tires down the road? If so then I would look at upgrading the rear axle. Dana 44's are a great option, I have them in my 87, but most of them have a different lug pattern than you front dana 30. You could look at a Ford 8.8 rear, they have the same pattern as your jeep does. another thing to look at is what gear ratio you have now. My wifes 88 is running 33 x 12.50's with 4.10 in the axles and drives great.
As far as the 4.2 goes a good carb and converting ignition to HEI makes it 200% better than the stock set up.
I have to agree w/ Jack. As long as the 4.2 is in good working order, a good tune, upgraded ignition and a good carb will make all the difference in the world. The MC2100 carb can be found all over the place for cheep and works very well at angles.
What do you have planned for the Jeep - how do you plan to use it? I think it's important to have a good idea of where you want to end up so you can make good decisions, and upgrade stuff just once.
I think Dana 44s from a full size Wagoneer are the swap of choice. You will have to regear them, since most of those vehicles came with 2.73s or maybe 3.31s. You will need a new set of wheels since they are 6 on 5-1/2 vs. your current 5 on 4-1/2 bolt pattern.
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How big is your wallet? It would be awesome to have two built axles built to your specs ready to bolt in. There's a company on Pirate that does this. And for what you get it's reasonable. If you want to do the budget thing, these guys have you covered. It's hard to find D44s that aren't full width. 8.8s aren't all that great either, but are better than a D35 and they are cheap and easy to get a hold of. I'd keep my eyes open for someone selling on C-list or here, or Pirate.
To keep it short, in my opinion a stroker is a waste of time and money on an I6. I looked long and hard in to them, and after you are nickle and dimed to death it's just not worth it for the small hp/tq gains. Do a V8 swap before doing that. So easy to do that in a YJ.
I am in the middle of an 8.8 swap and from the specs stock to stock the 8.8 has bigger axle tubes, bigger ring gear, disc brakes and some other odds and ends that make it better than a d44. Just google 8.8 swap into yj and you will see what i mean. Dont get me wrong about d44's they are great axles but for the money a ford 8.8 from a 96 and newer explorer is better. And belive me the mc2100 is awsome. I personly have a 2.5L with fuel injection but ride in dad's (jacks) jeep and in is great everywhere
2006 f250 powerstroke 6" lift with 35x13.50's 2011 vw Jetta tdi 1989 Dakota. Sitting on d44's and 37's
Thanks for the great advice. The 4.2 does run well from what I am told by the wife since I am still in Iraw. I'll research the MC2100 carb and HEI ingition. That sounds like an easier project than building a stroked 4.0L. Even though FI would be cool, that's a costly upgrade.
As far as what I want to do with the Jeep, that is another issue I have. I'm not sure. Hitting trails and being able to get over most opsticals is important, but playin the mud is fun as well. I'm not so sure I want a hard core rock crawler, but something I can enjoy.
Again thanks for the tips, at least that gives me some ideas and possibly something to work on while on my comp time off.
Google "dirt cheap TFI HEI ignition jeep" and you can find the info you need to do a fairly simple cheap HEI ignition upgrade on the 4.2. Basically (if memory serves) it uses a Ford TFI ignition coil with a GM HEI module and the (Motorcraft) distributor that fits your engine. I don't recommend using the cheap WELLS brand module or any other parts, unless you plan on keeping spares handy
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Post by ScramblerPat on Mar 3, 2010 8:45:22 GMT -5
Sorry to come into this on the tail end.. As far as the 4.2 goes, if you put money into a good running 4.2 it will end up being your most regretted upgrade. drive the 4.2 and look for a junk mid 90's 4.0 with mpi. pull everything including the computer (many folks in T4W have the connections) and put the 4.0 engine and fuel injection in you YJ. As far as axles that will depend on your wallet, locker, tire size and skinny pedal decisions.
P.S. I have made all the "other" choices!
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Well I think we've came up with a plan for our YJ. It's not going to be a hard core rock crawler but something we can trail ride with and possibly plan in the mud with. We've decided to have it lifted 3.5 in so we can run 33s. We are now searching for a 8.8 rear end to have swapped into the vehicle so we can run bigger gears. We are going to lock up the front and rear. While all that is going on we are going to keep searching for a good deal on a FI 4.0 engine.
I was fortunate to find an 8.8 with 4.10 today at PNP out of a 97 Explorer. Can't beat the price with their 20% off deal. I was able to get it for less than 150. Only took two trips, one to find out if they had the axle of choice and the other to bring the required tools and some help to pull the axle. I see more shopping at PNP for any future projects.