MissManche88 Posted June 20, 2014 Share Posted June 20, 2014 I have yet to begin this endeavor, I was hoping I could get some advice first. So my girl, 88 pioneer was stock with a 4.0, aw4, 2wd. Right now I'm still running that engine (with serious over heating issues, damn you closed cooling system.) With over 200k miles on her, same transmission, with an ax15 waiting for her in the garage, I ditched the beam and the turdy5 for a hp30 and 8.25 (the hp30 is acting as a beam cause I haven't had time for the 5spd swap, so the np241 I have is keeping the ax15 company). She's spring over in the rear, lift Springs with spacers in the front, on 35s. I also need to tackle some frame repair.. =\ Anyways, I also have a 1985 Chevy k20. Real 350 (4 bolt main) auto trans (th350/400) with a full floating 14 bolt rear and a 10 bolt front. Now I know this is no Chevy forum so I'm gonna try and keep this 99.9% manche related. I go through transmissions in the chev like I change my socks... so I've decided to use my half a monster truck as a donor for my #1 girl. Comanches are hard enough to come by around here, forget about anyone that wants to appreciate them. (The only other 2 around are owned by grumpy old men) Now I've done a little research on this so far and haven't come up with much. But I can take the 350 out of the chev, put it in manche, get an adapter for an absurd $300 and use my ax15 and keep the 241 case. Or I can put the 350 in manche, get a sm465, then I'm sol for a case (my collection consists of 1 np241 from an mj, 1 or 2 np241s from chevys and 2 or 3 np208s from chevys) yes I have a parts collecting problem. What more would you expect from a girl who loves her trucks more than most people? Regardless. None of those cases work with a sm465. Now. Questions being do I buy the adapter and run the ax15 with the np241, or search for a np207 and sm465? What do I do about a radiator? Can I take the one out of the chev and run that in the manche or will it not fit? I don't think I have to worry about axles, but 355 gears.. Should I worry about axles? I know drive shafts is a whole other story, I'll drive off that bridge last if I even make it that far. The sm465 makes me nervous because I read somewhere you run into height and floor issues and have to start cutting things and that's just not okay with me. I know there's an awful whole lot that goes into a project like this, and I've never tackled anything of this magnitude especially on my own, I'm just looking for a few answers and maybe some advice before I start ripping engines out of either of my trucks. BUT if I get the 350 in my girl then I can start looking forward to a 632 for my man ;D (that's the Chevy) any comments advice answers or kind words are welcomed and appreciated. Sorry for making this post huge.. Link to comment Share on other sites More sharing options...
benjy_26 Posted June 20, 2014 Share Posted June 20, 2014 Throwing a 350/SM465 imto a Comanche is going to take a lot of time, money and effort. Sometimes having the parts available isn't a good enough reason to toss em into a vehicle. What do you see yourself doing with the MJ once the build is complete? Is a 350 going to be able to do something for you that a properly built 4.0HO or stroker WON'T do? Link to comment Share on other sites More sharing options...
Eagle Posted June 20, 2014 Share Posted June 20, 2014 I have not yet encountered an MJ with a SBC but I have seen a number of XJs (Cherokees) with SBC conversions, and every single one of them had major cooling issues. Not what you asked, but IMHO you would be much better off to rebuild the 4.0L, maybe into a 4.5L stroker, and keep the MJ an MJ rather than make it half Chevy. Link to comment Share on other sites More sharing options...
Incommando Posted June 20, 2014 Share Posted June 20, 2014 A never knew that Jim lived in Connecticut? The source for any of your 241's could not have been a Comanche. They only came with the 231. The XJ had a 242 available but it has an all-wheel drive option. The only time the 241 was used in this series was a few '05-'07 KJ's with the pretty rare 6-speed stick option. The reason this becomes important is getting the correct spline count and input/output lengths for any swap. Although the 208 should be is passenger side drop most Chevy 241's are from the driver's drop IFS era. Any jeep 241/231 would have the front driveshaft output on the driver's side. The differential on the 10-bolt is on the passenger side. Using a D300 sourced from a later CJ is an easier way to match your AX15 to that front axle.. As to the 350: If you want to do it go for it. But know that it is not an inexpensive or quick process. You will also encounter cooling problems. You will spend time and money correcting those. Why not use the effort to fix your current problem instead? Closed systems can certainly cool a 4.0. You could also swap to an open system or upgrade your current one through one of the many posts on here and the XJ forums. 4-bolt mains may aid longevity but do nothing for power. Many many 4.0's hit 300,000 miles. How many 350's do? The longevity winner is the 4.0. Putting the 10-bolt in the front will not be easy. Many swap to leaf springs in front as an easier way to go to heavier axles then adapting the donor front axle to the flexier factory link suspension. The only thing that 10-bolt has over any other 10-bolt is the bigger brakes. It is considered equal to a D44 front, uses the same axle u-joints as a late-model HP D30, and is just 1 step up from the HPD30 on the strength scale. Maybe using a truss (internal or external) on the HP30 along with C-gussets and chromo shafts would be worth looking into versus the 3/4 ton axle swap? Chromo's for the 8.25 are cheap and such a set is used with 35's just fine. While super strong and super cheap to find, the 14 bolt is also super heavy and super low-hanging. The weight of the axle and the dynamic forces it brings into play generally means a chassis failure eventually and yours is apparently already weakened. Choices choices choices. Link to comment Share on other sites More sharing options...
MissManche88 Posted June 20, 2014 Author Share Posted June 20, 2014 I very well could just put a 4.0ho in her, I clearly just like making things difficult. The extra case I have that I was told was out of an mj very well may be a 231.. been a while since I organized my collection and double checked exactly what everything was. But I do know they're all passenger side drop. I want to keep my manche as manche as possible,which is why I was considering doing the 350 with the ax15. I also wasn't much at all considering swapping axles. I don't want to say she's a road Queen, but for what's around here as far as offroad goes, I consider it fairly light and not necessary to go crazy building a superduper mud truck or rock crawler. I also don't particularly see traveling for trails in my near near future. But come on boys, what girl wouldn't want a sbc in her manche? I didn't realize cooling would be such an issue. Maybe I should gather parts and sbc my 89 manche that's just hanging out in the garage? Practice makes perfect, right? I guess maybe I should reconsider the whole idea. I'm running out of room for all these vehicles, I was hoping to potentially consolidate or downsize, and I've never been a huge fan of selling my trucks. I've actually never sold a truck. Hah! I appreciate the information, thanks guys. Link to comment Share on other sites More sharing options...
Zebvance Posted June 20, 2014 Share Posted June 20, 2014 As stated before Cooling is going to be a major problem. Simply not enough room for enough cooling. You will be spending $500+ on a custom made radiator to keep up not to mention throwing upwards of 8000 cfm in electric fans to push all the hot air out. I have a buddy that was going to throw a ZZ4 he had with a TH350 into a 98 Wrangler. He found a novak adapter on craigslist to mate the th350 to the np231. Long story short his TJ was so rusted he decided to ditch it and traded it for a boat. He still has the adapter and Two Th350s and he is trying to sell them right now. I think he wants like 200 for the adapter. Which I think Is pretty goo considering they are like $600.00 new if I recall right. Link to comment Share on other sites More sharing options...
Incommando Posted June 20, 2014 Share Posted June 20, 2014 Just a quick comparo: 1985 K20/K30 350/5.7L: 160 horsepower/ 260 #'s TQ with carb vs Renix 242/4.0L: 177 horsepower/225 #'s TQ with fuel injection. Sorry. Not a SBC fan. They were cheap and plentiful and therefore popular. Those are not the criteria I use for choosing dates or engines.... :rotf: If the 231 or 241 is passenger drop it wasn't from a Jeep. There is a gear-shaped tag on the rear of the t-cases that will tell you what they are. If you aren't using that 10 bolt none of your transfer cases will work. You either need to swap axles or buy a T-case. Note the differential location on your D30 versus the front output on those t-cases. Not to be too much of an @$$ but if that isn't obvious then a major swap like this might ought to be reconsidered unless you are farming it out. http://www.chuckschevytruckpages.com/enginespecs.html Link to comment Share on other sites More sharing options...
Zebvance Posted June 20, 2014 Share Posted June 20, 2014 Forgot to mention I have seen it done before (sbc in a mj). It was a tubed out mj crawler. To keep it cool he piped the radiator to sit on the tube frame behind the cab and had electric fans on it. Like a lot of pre runner rigs do if you are familiar with them. Could you imagine trying to burp that system?!?!? It was a Sweet rig though Link to comment Share on other sites More sharing options...
husky410ohio Posted June 20, 2014 Share Posted June 20, 2014 I have done this please see my pictures here. posted in the PUB forum: Willys Jeep Rally 2014, College Corner, Ohio, May 30/31http://comancheclub.com/topic/43152-willys-jeep-rally-2014-college-corner-ohio-may-3031/ Link to comment Share on other sites More sharing options...
jimoshel Posted June 20, 2014 Share Posted June 20, 2014 Never could understand the "Chevy into a Jeep" thing. I have done a "couple" and they turned out OK. Personally I prefer a small block Ford, and I'm not a Ford man. Primary reason is because they're 200lbs lighter, 2 inches narrower, the dizzy is in front of the engine and usually a couple bucks cheaper than a Chevy. To each his own. :cheers: Link to comment Share on other sites More sharing options...
benjy_26 Posted June 20, 2014 Share Posted June 20, 2014 A buddy if mine has a 4.9 stroker in his XJ. He runs TWO radiators with puller fans to keep his rig cool. Remember, the more power and displacement, the more heat is generated. One V8 swap I would love to see in a XJ/MJ is the 1UZFE out of a Lexus. It's super durable (people call it the million mile motor for a reason), is relatively light, mates up to toyota boxes (should also bolt to an AX15 with some finaggling), and puts out a lot of torque. Besides, you can still tell people you're running a 4.0 without lying to them. ;) Link to comment Share on other sites More sharing options...
Incommando Posted June 20, 2014 Share Posted June 20, 2014 Never could understand the "Chevy into a Jeep" thing. I have done a "couple" and they turned out OK. Personally I prefer a small block Ford, and I'm not a Ford man. Primary reason is because they're 200lbs lighter, 2 inches narrower, the dizzy is in front of the engine and usually a couple bucks cheaper than a Chevy. To each his own. :cheers: Yep. The low-deck 289/302 are especially suited for that. The rear dizzy is a killer in some swaps but you know...everyone else does a SBC so might as well join the crowd. :doh: Buick V8's are also relatively lightweight and have a front dizzy. Link to comment Share on other sites More sharing options...
jimoshel Posted June 20, 2014 Share Posted June 20, 2014 The 350 Buick is always my first choice for a swap. Lightweight compact and reliable. "everyone else does a SBC so might as well join the crowd" Sorry. What everyone else is doing will NOT affect MY thinking. Link to comment Share on other sites More sharing options...
husky410ohio Posted June 21, 2014 Share Posted June 21, 2014 For me the I purchased the 88 4wd 4cyl for $100 (did not run) paid $100 to have it towed. Purchased 87 Comanche $100 for parts. My brother gave me the 350 chevy targetmaster 4 bolt main 350 and the SM465 with holly 650 cfm spreadbore double pumper carb (was in his CJ-7 and ran great). The motor mounts are made for this conversion from advance adapters and I also got the transmission adapter to the NP231 to SM465 from AA (spud shaft type) and also added the slip yoke eliminator from AA. The radiator is from Novak for this conversion but you have several companies that make radiators for the chevy motor conversion. Summit Racing has radiators too. I have an electric pusher fan in front and fan/clutch mechanical motor fan. I measured the drive shaft lengths and had custom clutch in Canton Ohio build me new drive shafts. I have many hours building and spent about $8000 (did not keep track how much I spent but this is what wife thinks it is). Note the fan and clutch I used are from the Jeep 4cylinder motor but the 88 fan was a reverse flow type (88 had a serpentine belt). I just put the fan in from the 87 which had clockwise rotation fan. I have not run it with the clockwise fan I have the gauges off and fixing fuel gauge now. Also the headers are made for the conversion I got from AA. Link to comment Share on other sites More sharing options...
MissManche88 Posted June 21, 2014 Author Share Posted June 21, 2014 Good food for thought. Like I said, just trying to keep my options open and maybe make a little extra space out of the deal. Looks like I've got a lot to consider. And I always like to keep my options open. thanks boys =) Link to comment Share on other sites More sharing options...
jimoshel Posted June 21, 2014 Share Posted June 21, 2014 boys? Well I call 'em girls so why not? Link to comment Share on other sites More sharing options...
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