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Sawsall proved to be a poor candidate to extract a late model firewall

BenWheelin

NAXJA Forum User
Location
Texas
Is my Jeep modified enough to post here? I drilled all of the spot welds, modified the inner fenders, and welded the entire core support from a 92 into my 86. I have a clean engine bay, clean firewall on both sides, and pretty much nothing forward of the body wiring harness connectors. This was all pretty simple, actually.

When I went to practice on a junk tub, I found my plan of changing the center of the firewall to be more involved than I previously anticipated, namely, extracting the section with a reciprocating saw may not have been my brightest moment. So despite my abhorrence to unwarranted violence, I've decided to go the sledgehammer route in my quest for 4.0 clearance, while using hole saws for the shift cable and trans control wiring. I understand that this is a fairly unorthodox swap, but I was hoping some here may have pictures of the end result.

Also, now that you've had adequate time to shake your head, know that this is a well equipped two door, the transmission from which more than paid for this entire project, and my only out of pocket expenses are bits, blades, and paint. Thanks for posting.
 
I actually have an excess of pictures which all proved fairly useless in the project so far, but I imagine they could be of some use to one considering a core support swap to convert a 2.8 (or 2.5) to accept the wide radiator and modern hood latches. I'll get them uploaded.
 
I'm sure that was a ton of work, kudos for tackling such an ambitious project.

On a side note for anyone else considering swapping a 2.8 in favor of a 4.0....

An LS4 is the same bellhousing pattern as the 2.8.

You get an all aluminum 5.3 liter V8! Just have to fab some motor mounts, some headers, and a starter mount.
 
Pics?


Seems like no one on this site owns a camera.

A lot of it has to do with people getting boned by photobucket and not taking the time or not being able to move their photos to another service. Photobuckets download service also seems to have a lot connection issues lately with lengthy repair times
 
Apparently the pictures cease at the mock up phase just before welding. I have some potato pictures I could dig up of in between welding and engine out.

Here was the problem with the 86 when I bought it. V6 was running great when it came out.

0618161103.jpg


Early and late lower core supports.

PA090022.jpg


Corner braces extracted and ready.

PA110026.jpg


Late model inner fender profile, left.

PA110032.jpg


Late model inner fender profile, right.

PA110033.jpg


Template made from late model inner fender and donut box from coffee shop.

PA120060.jpg


Mock up with all braces in place. Note that the frame has been cut and laid over, I'd suggest that you weld in the lower support top and bottom before laying it down. All of the vertical studs in the area are removed. I also took the opportunity to create a bit more clearance for the lower transmission line, (going auto because cheap) and I made a notch for a hose on the petcock on the opposite side. No more draining coolant everywhere.

PA120062.jpg
 
I actually did a good bit more trimming after that last picture and before welding it all up. You can tell I folded that side first.
 
I'm sure that was a ton of work, kudos for tackling such an ambitious project.

On a side note for anyone else considering swapping a 2.8 in favor of a 4.0....

An LS4 is the same bellhousing pattern as the 2.8.

You get an all aluminum 5.3 liter V8! Just have to fab some motor mounts, some headers, and a starter mount.

I already have a 5.3 donor waiting for another project, a 57 Townsman wagon, but that's another forum. I don't even know why I'm doing it, I was in the middle of building a 90 until I came to the conclusion I'd have to pull the engine for freeze plugs. A compression test revealed I'd rather put freeze plugs in a low mileage donor engine out back, and then I decided that maybe I'd just put it in this one because I drove it for a while and I like two doors. I'm gutting a low mileage 92 to build both but the other one is staying Renix, and I like Chrysler fuel injection better. On that note, I'm getting rid of all the Chevy stuff from my Jeep short of the steering column and box, which will still be late model spec with a shared ignition and door key.

I also have a ZJ with a 5.2 I could have gutted, but this is the best of what I have to choose from. The 4.0 from the 92 still runs fine, but I flogged it hard across Arizona for a week and loosened it up a bit. It'll suffice until I have it organized and I'll drop the better engine in resealed later.
 
The 5.3 LS4 is a different animal than an LM7. They were redesigned for front wheel drive and have the active fuel management

I'd say I understand, but the interest just isn't there. I have several Chevrolets in various states but I choose to build a Jeep at the moment. A 92 Laredo two door with a 4.0 is hard to find around here, and it's what I want. 75% is plug and play. The fun part is going to be splicing the body harness, or modifying the late model four door harness to fit the two door. I'd rather just replace the fuel tank circuit and leave the rest original in the rear.

I also have a 92 Laredo I paid $300 dollars for, built a nice rig out of, then discovered the lien.
 
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I swapped the lower/center of the firewall only on a 85 2dr. Worked great but had to swap heater box also. What I didn't take into account until my starter went out was the top starter bolt won't come out....LOL Don't forget to check that...
 
I swapped the lower/center of the firewall only on a 85 2dr. Worked great but had to swap heater box also. What I didn't take into account until my starter went out was the top starter bolt won't come out....LOL Don't forget to check that...


It's things like this I like to know. I see no difference on that side, wouldn't expect it in a million years.

The HVAC cabinet is already out, and the AC worked great in the donor, so everything gets swapped. I'm waiting to break the system so as to have as little time open as possible, but I like the idea of cold air in an 86.

Do you run antique/classic tags? I have a pair of Texas sesquicentennial tags for mine. 1836-1986.
 
True, I was assuming auto trans...which could be built for the v8 power.

Honestly, I bought the Jeep for $250 and put a thousand miles on it, then needed an AX5 for a four cylinder model, and anything which can fit a Wrangler is stupid expensive around here. It pretty much paid for itself. I'm boxing all the manual transmission stuff that comes out and saving it. Couldn't justify putting anything back in behind the V6, and I have enough AW4s to last until I die.
 
Cut-off wheels, a plan, patience.

Not a BFH!


Oh boy...........

Chuck the clump, strip the bay, clean up your mess..........then cut.

Yeah, I'm pretty much there. In fact, the cutoff wheels are already purchased. I just haven't tried that hard, I guess. Fortunately, I'm practicing with junk before I cut either the project or the donor.

Unfortunately, the junk tub is an 89 and it has plenty of extra holes I won't need. I could just fill, but I'd rather extract the "top right corner" where the throttle cable passes through, getting that three inch lip under the pinch molding that allows you to remove your valve cover, but not enough to add the trans control wiring hole or the one for the shift cable. I'll just holesaw those.

Someone got mad at it once, and I'd like to repair that because it looks terrible. At least, with the engine out.

Can't wait to find out what the 4.0/AW4/4.10s drives like on 33s.
 
It wasn't all that difficult, once I resigned myself to removing the wiper transmission. Thought I could get away without it. I absolutely destroyed the donor tub in removal.

PB260008.jpg


The fun part was separating the layers, as there's three at the base of the cowl. Here's the flange under all of it.

P1010020.jpg


I opted not to cut all the way to the right, settling on straight lines. The throttle cable outlet is lower than Renix, which is lower then later Chrysler models. The lower right hand corner was a must as that profile doesn't exist in the older one, and at that corner is a crease in the body also not seen later on. It made for some fun flanging that corner.

Fun fact, cut a line where you wish to remove the original seam sealer, heat from behind with a heat gun, lift an edge, and peel.
 
Engine is in. Transmission cross member doesn't line up to anything underneath. Opening on the left is larger after 91 or so. Lots of fun stuff left to do, so I'll start another thread detailing the finer points.
 
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