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19trax95's 1986 CUCV M1028A1

16060 Views 358 Replies 24 Participants Last post by  19trax95
So I have been looking for a decent square body for some time now. Didn't really have my eyes on anything in particular, but the frame and body needed to be in as good of shape as I could find.

Last week I came across this beast on marketplace up in Massachusetts. It's a 1986 Chevy M1031. Which is the military CUCV service truck.

It is I'm great shape. Frame is rock solid, and the cab has very, very little rust. It is also mechanically sound. A couple little leaks, but that's to be expected.

It has the 6.2 diesel, th400 trans, np205 t case, king pin Dana 60 front axle with a limited slip, 14 BFF rear with locker, and 4.56 gears. The service body is all aluminum. It used to have a PTO driven generator and air compressor, but those have since been removed. The PTO is still on the t case though.

My plans are to keep it fairly original, but add a few creature comforts to suit me better.
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I measured the truck today and the front settled a little. Still have no rubbing or anything though.

Front fender height measures 43.5" and the rear is 42". I think it's actually a bit more than that, based off looks, but where I measured it wasn't exactly the fattest ground either. So I gave the rear block to my father and I'll have him machine off 3/4" off it so it'll be a 3.25" block in the rear.

My reason behind this, is so I will have a little rake to the truck, at around 1.75". This will allow me to add the front zero rate if needed in the future and still have the truck be higher in the rear by 3/4".

I just feel like the full 4" block will be more rake than I'm after.

Oh and I also gave the truck a quick wash today.
Car Wheel Tire Vehicle Plant
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I plan on removing them if they are installed like I believe they are. For my uses, I don't need them for anything, however, they are more than just a run flat. They also work as the bead lock for the inner bead. The outer bead is held on by the lock ring, but the inner bead gets held on by the clamping force of that insert. They make pvc inserts that function only as a bead lock. They are around $90 per tire though. So basically $400 for all 4. Another option is to cut the run flat part off the normal inserts and just run the center part. That's free obviously.

But I don't forsee myself ever airing down to the point where I'd need a double bead lock. Nice to have though. Also makes it so if I do go flat, all I'd have to do is add air and not worry about seating the bead.

Part of my plans this spring/summer is to build a custom headache rack for it that will add a little something to the rear of the truck. I'm also still looking for the period correct antenna for the truck. Especially since the bed already has holes for it. I do believe this bed came off a communications truck since it has the bus bar in the bed still for power for the radio equipment.
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Yeah it's not too fun lol. Then again their is removing the stock inserts lol.
Block are machined down and new center pins made. Also changed the title to reflect the trucks new configuration
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Automotive tire Rectangle Automotive exterior Gas Auto part
Wood Gadget Audio equipment Rectangle Automotive tire

Rectangle Wood Audio equipment Automotive tire Gas

Hood Automotive tire Automotive lighting Helmet Grille
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Well plows on for maybe the last potential snow of the season. Wasn't too fun to get on there lol. Had to use a floor jack to lift it up. Then the chain wasn't long enough to let it touch the ground once it was on the truck.

Had to rig up a temporary fix of another section of chain added to it. I'll fix all that in spring when I redo everything.

The tires also touch the fenders when turning and the plow is raised. So I will be adding the zero rates to the front. But it'll work for now. Might mess up the edges of the fenders a bit, but they were getting replaced come spring anyhow lol.

Tire Wheel Automotive parking light Vehicle Car
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Yup I definitely can. I wanted to this year, but we didn't get any snow. This storm wasn't plowable either. Got maybe 2" on the grass. But the rest melted off.

I plan on getting some driveways in my neighborhood and locally. Plus I'll do the lot at work since our plow trucks are rusted out, decrepit ford's lol.
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Well the weather just has not been very cooperative lately. Its nice during the week then the weekends are crappy.

Once spring finally get here to stay, I will be tearing into the turbo project. At the same time I'll add the zero rates as well as the rear block, brake hoses, etc. Once that is done, and turbo setup is up and running good, I will be beginning the body work.

I do have some side work that will get ahead in line since those are paying jobs lol.
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Sold the service body this morning. Was one of the easiest sales I've had on Facebook marketplace. And perfect timing. Guy looked at another one, and it wasn't in great shape. I just so happen to post mine and he seen it. Messaged me this morning at 7 saying he can be there with a trailer in 30 minutes.

Showed up, looked it over, and gave me the cash. No haggling or nothing. Probably means my price was too low, but I got what I wanted out of it, and he has a nice service body for his start up business. So it's a win win.
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Will be starting the turbo swap fairly soon. Lately I've just been driving the truck and nothing much has been getting done on my own stuff. I'm taking a break from side work for a while to get my own projects rolling.

We had a fire at the farm last night to get rid of the old trusses from the barn. He raised the roof and extended it length wise so there was quite a bit of wood to get rid of. We dug a fire pit in the pasture and went through a fair bit of wood.

Was a decent photo opertunity so I grabbed a couple lol.
Automotive parking light Tire Wheel Vehicle Car
Land vehicle Wheel Tire Sky Car

Tire Plant Sky Vehicle Car
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Just ordered my hose and fitting to make my oil feed line for the turbo. Got it all through jegs.

I'm making it out of -4 AN line. It'll be a 90⁰ fitting off the turbo, route back to the driver's side rear corner of the motor, which is where I'm going to tap the oil off of, then to a -4 AN fitting to 1/8" NPT adapter into the oil galley port that is currently used for the oil pressure switch.

I will be installing a T fitting so I can keep the switch (which I will be swapping for a sensor and adding a gauge for said sensor).

So now the only part I need to buy, is a V band flange for the downpipe adapter. The rest I either already have, or will have to custom make. I am still debating buying an exhaust for a gmt400 truck with a 6.5 and modifying that, or just doing it my own way and building the entire thing. But that'll be something I can figure out once the turbo is in, and I get an idea of clearances and such.
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So I will be starting this turbo ball rolling this weekend. Likely Saturday night after I do the oil pan on my neighbors wife's car.

I have some cummins specific fittings ordered through work and the rest I have pretty much. I need one clamp for the downpipe yet, but that's also on order.

Will post pics as I go.
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Got the old passenger side manifold off, and both exhaust flanges off the manifolds today. Both batteries are out as well. Went to install the "new" 6.5 manifold on the passenger side and found the bolts I got aren't really long enough.

So I'll grab some new ones that are the correct length at work tomorrow and put the manifold on. I could have put it on today but then I'd have to swap bolts and all so I figured I wouldn't bother. All the bolts came out without any issue at all except for one of the studs on the passenger side manifold, which doesn't matter since it won't be reused.
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Made a little progress tonight. Got the 6.5 manifold on and torqued, which let me tell you, absolutely sucked lol. Had to zip tie the bolts so they wouldn't fall out as I fished the manifold in there. Then make sure the gasket didn't get damaged. Only to find the bolts were literally a millimeter or two too long so the heads hit the frame before the manifold would slip into place.

So I had to loosen the motor mount, take a big pry bar and lift up slightly on the engine, hold it with one hand, and slip the manifold, 8 bolts, and the gasket into place and start the bolts so they clear the frame.

But it's on there and has clearance now that it's in.

I set the turbo on there to get an idea of the room I'll be working with. The intake won't be an issue I don't think. The exhaust is going to be by far the most time consuming part of this project. Will be lots of trial and error I have a feeling.
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It wasn't too fun, but considering how fairly significantly larger the 6.5 manifold is, it's not awful i guess. The factory one is a breeze to remove and install.
They are pretty small for sure. Really they are roughly the same size as the 6.5 ones on the inside, just the exterior of the 6.5 manifold has more meat on it since it needs to hold up a turbo
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Well jegs sent me the wrong fitting. The package was right, but the part inside was not. Got hopefully the correct one coming to me tomorrow. Tonight I'm going to start to tackle the crossover pipe. That way once that's done, I can do the intake, turn the pump up, mount the turbo, and run my oil feed and drain lines, and fire it up.
They are usually pretty good. Shipping is quick and prices are good. I've ordered a bunch of stuff from them and this is the first issue I've ever had. Was a $6 fitting so it's not even worth the hassle of returning lol
So I put in almost 4 hours of work, and don't really have much to show for it lol.

I am close though, and the design is finalized, so all that's left (for the crossover anyway) is to tack the two parts and then measure the pie cut I need, cut that, and weld it in.

So the 6.5 crossover I bought obviously wouldn't work. Wasn't even close. The shape was about right, but the angles are all wrong. And the flange on the driver's side was too big. This is due to me retaining the driver's side 6.2 manifold.

So, I salvaged one of the old flanges and then decided I'd put a flex bellows on the one side to help kill any vibrations, and to prevent damage to the manifolds should anything come into contact with the pipe.

This was the easy side. The passenger side is a different story. The angles on this side were all WAY off. So I cut the flange section off, measured how far I need to come down, cut again, then got it so that that section will contact the rest of the crossover by one edge. So all that's left is to tack it, then do some CAD work and ultimately cut a pie section out of a scrap section of pipe and weld it into the gap.

Don't mind the hideous welds, it's stainless to aluminized so it doesn't like to weld the best lol. But they will hold and not leak. I was able to get the clearance to the oil pan and trans bell housing down to about half an inch. That's as close as I wanted to go. I will be painting this with some high temp paint and then wrapping it with some header wrap to try and help keep as much heat in the exhaust as possible, and away from things I don't need to be any hotter lol.

But so far I'm happy with it.
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Crossover is done except for paint. I thought I had some left, but I don't. So I'll order some from napa tomorrow at work.

As you can see from the picture, I opted to clearance two spots to allow more room between the oil pan and then the one ear on the trans bell housing. Ended up being a little closer than I planned on, so I wanted to have at least a half inch of clearance. The little massage got me to 3/4"

Also got my correct fitting today for the turbo oil feed line.

Next up is the intake swap and turning the pump up while it's off since I'll have easier access to it.
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