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Project:Unicorn

SAMSET

NAXJA Member
NAXJA Member
Location
Bourbonnais IL.
OK, so i bought this XJ a lil while ago but i was trying to get some more work done to it before i started a thread. Not much has been done at all, im just at the point where i may need to questions answered so i figure might as well get the ball rolling.

This guy at work found out that I was into xj's, he tells me one day that he has a mint 2 door he wants to sell me for cheap. says this thing has no rust on it at all, motor is brand new, and its just sitting in his dads garage(dad passed away 5 years ago) his dad was building it up to be just an all around cool rig. my response was that there is no way you have a clean as new xj sitting up in northern IL. he kept telling me he is going to take me to go check it out soon. (Woodstock IL.)

im down, right. my current jeep is a rusted out piece of crap, you all know that:cool:

now the reason its title this way. i agree to go check it out, but this guy keeps pushing it off. i say lets head up there this weekend he agrees and the cancels days later. weeks turn to months and so rew and i agree that the rust free 2 door xj with a brand new motor is a mythical creature:Unicorn.

finally one day i force him to make the trip only because im heading to Lake Geneva and driving threw Woodstock to get there. I have my hopes up to find a decent xj with rust assuming he just didn't know where to look, in a large shop with maybe a dead battery.

nope

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whoa right? this shop was the most cluttered up pile of amc parts i had ever seen.American pickers dream!!!
turns out that it originally came with the gm 6cyl. and dad pulled that crap and slapped in a 4.2 out of a 79 cj, WITH A 4 barrel and supposedly stroked. if everything he says is true it is a brand new motor with no miles and never started.
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after 1st glance i say no way to much work involved here, and im not skilled enough to tackle it. then he show me around the shop and is pointing at all the crap he will throw in with the deal(parts wise) so i decide to give it another look, i get up underneath and confirm that the is literally no rust on the jeep. i pull back the carpet in the cargo area and still pretty red paint and no signs of rust. looking at all his parts i come to the conclusion that he is in possession of pretty much everything to get it rolling. after a couple weeks of thinking about it i decide to buy it.

well the unicorn still hunts me. i tell him i want it and once again we cant get up there to go get it, he pushes it off week after week. finally one day few months later we link up, he has a truck and trailer and i have my companies parts van. hes bringing the jeep and i have an entire e150 filled with random xj stuff. on the way home the trans blows in the f350 dully he was using to pull it. just so happen to be so close to his brothers that we trucked on there. and there it sat for about 2 more weeks. this thing just didn't want to come home to its new daddy:flamemad:

finally couple weeks later we managed to get it to where i work and park it in our back lot. there it sat for a couple more months. i wanted it home in my garage and once again the guy i got it from kept pushing me off. then one day my boss shows up with his truck and trailer and decides to help. he tows it to my house.
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and there it found its new home
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since then close to nothing has been done. i added an alternator and bracket and some belts.

couple weeks ago my boss bought a xj and wanted a cheap lift. this thing had the block lift with an add a leaf and coil and shocks all for about 3in lift. pulled it all off knowing that i wont need it and sold it to him to make some money back.

me and Tim pulling the lift off
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btw the interior is pretty gutted
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So right no w the big stopping point is the fact that i don't have a steering column, carb, drive shafts, or gas pedal. all parts he claims are in his shop in Woodstock......yea, you guessed it, i cant seem to get him up there to go get these parts. worst case those parts are not there, i can pull most of that stuff out of my black one when i start that tear down process.

but the main reason i made this thread is because im dealing with something a lil older than i know. so talk carb to me, what is my best option and where do i got to look. i called one of my real good auto guys and he said because the 258 did not come with a 4 barrel he did not even know where to look. anyone here got a better answer than that. does switching to a 4 barrel mean you are using a carb from a different application? and if so can i find out what that application is?
 
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You would want some detailed specs on the motor build to get something in the approximately correct CFM range. Looks like a square bore manifold for one with fairly equal primaries and secondaries. I always liked the Holleys, and I'm sure they've improved them since the 80's.
 
i spent about 2 months this winter getting to know a 4.2L pretty well, but like stated above, you need to know some info about the motor to know what sort of carb it needs. the stock 258's had a 2 barrel carb on it, but if this one was retrofitted for a 4 barrel then there is certainly a reason for it. the 2 barrel was almost overkill for the stock manifolds...you may want to join ifsja just to ask some questions over there.

the other thing i would check is if it was built with a 4.2L block and a 4.0 head...it certainly doesn't look that way with the valve cover that is on there. i know a lot of folks do that swap though. personally i don't know about a stroked 258...i know you can use the parts to stroke a 4.0, but i was always under the assumption that a 258 is a stroked 232...something seems weird here.
 
Well the stroked part is not confirmed by any means, the guy i bought it from is a super hyper guy that talks up everything he sees. even my pile of junk is BAD ASS!!! in his opinion. i know i found a receipt for a cam and a few other motor parts with the title, so there defiantly has been some modifying. im hoping that i find the carb he bought for it in his shop if i ever get there.

i doubt that it has the 4.0 head, this shop had about 20 AMC motors laying around. i have a feeling he just grabbed one off the floor and slapped it in.
 
That there on top of the Jeep, is it one of these or close to it?

http://www.amx390.com/body.html


I believe so, im not sure what make it was for but im sure it was for an AMC. this guy had tons of stuff there AMC wise. even 1930s cord in mint condition, won some award as being one of the top in America. the guy i bought the xj from opened the garage so i could see it but wouldn't even let his 13yr daughter in there with us
 
well if you decide you don't want it, you can just sell it to me :) i had fun tinkering with that 4.2...it was my first carb rebuild/tune and engine tune up and i'll admit, it was kind of fun
 
for right now im really hoping this is going to be fun. i know it needs a bit of work but i kinda bought it for the long term project aspect of it. i feel like me and my buddies hanging out in the garage messing with it is why i bought it. just wish i had a bigger garage to do it in.

well just thinking today and i remembered that the guy who built this was a big fan of 4WD magazine and website. so i went on their site to check out manifolds and found this one
http://www.4wd.com/Jeep-Engine-Perf....aspx?t_c=74&t_s=46&t_pt=3566&t_pn=OFF5999-DP

which from the crappy pics i posted kinda looks like it. i did confirm that the motor is out of a 1979 cj(decoded the stamping on the side) so it looks like this would be the manifold that would fit...maybe...right?...

if so then that sight helps with the carb part of it to, so something like this may work...
http://www.4wd.com/Jeep-Engine-Perf....aspx?t_c=74&t_s=46&t_pt=3445&t_pn=HOL0-90470

maybe....right?...

now obviously i would need to confirm that's the manifold, but if so can, i trust that that would be the carb i need?


maybe...right?...
 
that one should work well...can you find what cam it is from the reciept? that would be a great clue as to what cfm you need...

either way you could do an anvenger like that and re-jet it if you are running rich or lean. that motor is really simple to work on.
 
that one should work well...can you find what cam it is from the reciept? that would be a great clue as to what cfm you need...

either way you could do an anvenger like that and re-jet it if you are running rich or lean. that motor is really simple to work on.


i should be able to. when i get home tonight i will find the receipt.

thats good news about it being easy, although im am thrilled to have a little garage project, i am an armature at best mechanic and most of the time have no idea what im doing:anon:
 
Wow!!! What a find! You weren't kidding when you said it was in good shape. It should be a fun project for sure. You'll certainly be very comfortable around mechanical work when all is said and done.
 
so this is the receipt from 4wd i fond with the title. i am told all these parts are installed already.

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there was no name on the intake at all, this number was stamped on it ef3237858 and as a parts guy that deals alot with dodge it looks like a mopar number to me.

firing order is also stamped on there 153624

so would he just have taken a amc intake off of a j10 v8?
 
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the intake is the same that i had on my j10...thats weird. he must have put a big adapter on it

http://www.ebay.com/itm/3237858-Jeep-CJ-258-intake-manifold-6-cyl-7-5-AMC-2-bbl-CJ7-J10-J20-Cherokee-4-2-/200809789349?_trksid=p4340.m1850&_trkparms=aid%3D222001%26algo%3DSIC.CURRENT%26ao%3D1%26asc%3D11%26meid%3D1518958106695627413%26pid%3D100011%26prg%3D1005%26rk%3D1%26#ht_600wt_955

thats the one i had on my 258...pull the carb adapter off and see what size the input is on the manifold under it. if he put a 4 barrel adapter on it he may have hacked it up a bit. if its not hacked up and you can get the adapter off, honestly i would get a 2 bbl adapter and run a motocraft 2100 carb on it. i got mine at a jy for $25 and the rebuild kits are cheap. it was about as easy to rebuild as any carb out there. it would be a lot cheaper than putting a big holley on that might be overkill for what the motor needs
 
yea there was a large adapter on it
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this is what it looks like with the adapter off

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so are you saying that this is just a modification, and if i ditch the adapter i can pt the original 2 barrel back on there? and i can find that 2 barrel in a junk yard for something like 25 bucks?
 
crazy..so there are 2 adapters there. the one in your hand in the top pic is a 4 barrel adapter and the one on the bottom pic appears to be a 2bbl adapter (what you will need for an mc2100). you do NOT want the stock carb, they suck major ass. the mc2100's are on most carbed ford trucks of the 60's-80's...you just have to match the flow rate to make sure you have the right venturi size. but its stamped on the side so its pretty easy to find the one you need...it appears that the adapter in the bottom pic would work, but at the same time it doesn't look the the 2bbl adapter that i used
 
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