1968 C40 to K40 pickup project BlueMule

[Old_Green]

Here is the cab pulled to the stretch distance, locked into place at all 4 corners. Then tacking sections into place. Some tapering will need to be done on the roof inner panels, as the roof tapers in toward the front.

[Old_Green]

I missed taking pictures during a stretch while I was welding the stretch sections. It didn't seem to be progressing, while doing that, but now looking back, I wish I had some documentation on it. During that time, I added strengthening angle iron between the front and rear sections, finished welding in the stretched section in the floor and inner rockers. For the outer rocker, I welded a couple of rusty sections over the gaps temporarily to add rigidity since I would be replacing them with new metal. The roof inner panel was welded up and I left the all-thread bolted into place. I then put the cab back on the cart and sent it off to have the entire thing wet blasted. It came back all clean.

[Old_Green]

I put a coat of epoxy primer on the cab everywhere I could reach. Everywhere I couldn't, I used cavity wax on a long spray nozzle.

[Old_Green]

I cleaned up the roof as best I could, and fit the roof front panel from the blue cab into place. I tried my new flange tool on the roof panel, to fit it under the rear roof panel and clamped it into place. I used some Cleco fasteners to fasten the 2 panels together. I tacked it into place, but the panels are pulling down at the seam, so I need to figure that out before I finish welding it down.

[LT7A]

You really decided to get after it! The cab is coming together nicely.

[Old_Green]

I'm still unsure about how to get the roof the way I want it before I finish welding it up. I need to think on that for a while, so I switched over to placing the engine/trans/T-case into the frame. I used the 250 engine perches, and the big block engine mounts were able to bolt right up. I would just need to make a transmission mount crossmember. I set in a temporary crossmember so the engine would set at 4 degrees down in back.

[Old_Green]

I set the front of the old cab onto the frame, but the firewall hits the drivers side valve cover. First pic is showing the cab mount bolt under drivers side needing to move forward about 3 inches. (Passenger bolt is in correct placement) I slid the engine as far forward as I felt comfortable with the fan to radiator clearance. I can move it forward about 1.5". second pic shows where I cut the floor out of my old cab where it hits, and placed the cab down.

Once I had the cab down, I bolted a fender on, and the core support, and placed the radiator in to check clearance. Once I was comfortable, I cut the rivets out of the perches, removed them, modified them to move forward 1.5 inches, and then got some grade 8 hardware to reinstall. Last 2 pictures are engine bolted in on modified perches with fan and header clearance.

[Old_Green]

First picture shows the section I cut out of the old cab to clear the valve cover, and the gap where it would need to sit to have clearance. it needs to move about an inch and 1/2. The last 3 pictures show the stretched cab where I moved the pedal section back 2" into the cab. I also leaned the bottom further in to gain additional clearance.

[Old_Green]

With the roof tacked into place, and the inner rockers all finished up, I used sections of new rockers from classic industries along with some original sections to stretch the outer rockers. I then bolted them into place in the front, and used a self tapper to hold the back and underside in place until I am ready to weld them in. I want to have the doors in place in order to check the gaps before welding them in. I then removed the inner support structure I had used, and cleaned up the welds a little. I also made sure the transmission tunnel cover fits and could be bolted in.

[Old_Green]

I started looking at the doors to start planning the door stretch. I found that both drivers doors have interesting upper hinges. The blue cab had an old church key used as a shim. The grey door the hinge had only 2 bolts. The factory paint was undisturbed on the third hole, so it was that way from the factory. Not sure if that contributed to it, but the hinge was ripped loose and it tilted the inner threaded plate bracket in the door.

[Old_Green]

I used some tips from another member on here, and built myself some door skin removal pliers.
https://67-72chevytrucks.com/vboard/...86#post5868686
Thanks for the tips Robert

I was able to use these for most of the vertical hems on the doors after Id used a spot weld cutter on the welds, but the bottom of the door, the angle is too tight for these pliers, and I couldn't get to the welds with the cutters. I was able to use a dremel to thin the welds out, and a flat blade screwdriver bent back a little over 90 degrees to pry the hem apart. Once I got it started under the skin, I'd pry it up a little bit, move the driver, pry it a little bit, move the driver until Id walked it the length of the door.

[Old_Green]

my thought is to pull skins off both doors in order to cut both the inner framework, and outer door skins to the desired size. Then when I have welded the inner panels together I can attempt to do my best to planish the seam. After that, I will attempt to do the same with the door skins. Hopefully it will all work out like it is in my head.

[MrBeast]

Mike, cool build!

I am looking forward to seeing how it comes out.

[Old_Green]

Originally Posted by MrBeast

Mike, cool build!

I am looking forward to seeing how it comes out.

Thanks, me too. It all makes sense in my head, its just whether or not I have the skills to do some of it.

[MrBeast]

Originally Posted by Old_Green

Thanks, me too. It all makes sense in my head, its just whether or not I have the skills to do some of it.

Well it is one of those things, you give it a shot, if you fail, try again, and again and again.

You know Try, cuss, repeat!

[350TacoZilla]

Great build and love the rear fender treatment. I'm planning to do something similar with a 63 GMC since they don't really get aftermarket fender flares and the factory ones fit the look so well.

[Old_Green]

Originally Posted by 350TacoZilla

Great build and love the rear fender treatment. I'm planning to do something similar with a 63 GMC since they don't really get aftermarket fender flares and the factory ones fit the look so well.

Thanks. I like the fenders that way too, I wanted them to match the front as close as possible so that it looks like it came that way. I still plan on changing the length of the flare somewhat on both front and rear flares where they meet up with the original running board, but that'll happen once I get the cab on and can do a little photoshopping to check it.

[Old_Green]

The grey door has a little less rust in it, and now that I have the door skin off, I can fix the hinge from the inside, so Ill use that door for the hinge side and keep the majority of the good metal. I will also beef up the door at the hinge bracket.

After much consideration I picked where I wanted to cut the doors. I scribed the cut lines then added tape with direction markers for which side of the lines to cut. I did some other work for a while, then came back and double checked my math. After about 15 times of doing that, I might be ready to cut.

I cut the grey door 7 inches from the latch edge of the door, cutting on latch side of the scribe. This will leave the entire regulator mechanism on the original metal. Then I cut the blue door 13 3/8 inches from the latch edge of the door, cutting on the hinge side of the scribe. I then cut 3/8 of an inch off where I couldn't flange the metal. This way, I can overlap the 2 pieces where they are flat, and butt weld where they arent.

[Old_Green]

Flanged sections.

[Old_Green]

I fit the 2 pieces together, and I'm pretty happy with the fit. But looking at the pieces, there is a lot of rust in the doors that I cant get to. I picked up a gallon of Evapo-rust and rust block and built myself a box that I could line with a heavy plastic leaf bag. I dipped the bottom edge of the blue door overnight in it, and you can see the difference by the line in the pic below, as well as the comparison to the first 2 pics. Ill pick up some more Evapo-rust, and see about building some containers to be able to dip larger sections in.

[Old_Green]

So, I picked up another 5 gallons of EvapoRust, and a longer plastic container.
The container is about 39 inches long x 16 inches wide.
I didnt want to fill the whole thing, so I built myself a cardboard box to fit inside the container, with just enough room to fit over the door end that I wanted to soak.
I lined it with a giant garbage bag to contain the liquid, and supported the cardboard with wood to keep the cardboard wall in place.
The first 2 pictures are of the hinge edge of the door sitting in my makeshift dipping tank.

With this setup, I was able to get the door about 6 to 7 inches deep in the EvapoRust.
That was enough to cover the entire inner support structure.
You can see the results below from the next day.
After this, I turned the door 90 degrees and put the bottom edge in the liquid for 24 hours as well.
The last pic is the stretch section of the door after a couple of soakings of EvapoRust, a little wire wheeling done on the flat sections, and a little rust inhibiting primer.

[Old_Green]

I added a couple of gussets to the upper hinge mount. my welding looked pretty rough, but they should hold.
I also found that a 1/2 inch OD steel tubing fits very snug into the hollow in the window frame and I can fit about 9 inches of tubing across the seam with 4.5" in each side. It should help keep the frame sections straight, and it will add strength to the frame when its all welded up.
I put 3 holes about an inch apart on the top side of the window frame on either side of the seam area to use to weld the frame to the tubing. Then I inserted the tubing into the frame sections, and clamped everything in place to check all my measurements.

[Old_Green]

Test Fit of the Door on the cab before finishing welding seam. Fit is pretty good. This was a lot easier to weld and keep flat and straight than the roof was.

[Old_Green]

I put the original glass in the lower channel to fit the extension piece. once it was welded into place, I moved the glass forward to original position to test the window regulator mechanism. Worked fine with this glass. I removed and cleaned the channel up and painted it. I may test fit it again once the new glass is ready. I may want to do that before I install the door skin permanently. I have also been soaking other random pieces in the Evapo-Rust as I come across them, to clean and paint.

[Old_Green]

I cut the 2 skins with 6.375" extra, and used my flanging tool to flange .375" of the blue panel along all the flat sections. After quadruple checking my measurements, I tacked it together. Once I was happy with the fit and overall dimensions, I moved to welding the seam on the front of the panel. .

I have messed up some good welds by getting too impatient, so I took my time, putting a stitch weld about every 3 inches along the length of the seam. I then hit it with air until cool to the touch before making another pass. I'm pretty happy with the result.

I test fit the skin onto the door frame, and it fits very well. I will pull it back off soon to test fit the full glass panels and the seals once they all come in. (wing window seals on back order)