1976 CCSB Duramax Project #trucknamedsue

[RADustin]

Afternoon all,

I have finally had some time to sit down and document the current project I'm working on. I've found through my previous '49 Chevy build that build threads are super helpful later on after the build and I figure some of you may find this one interesting.

As a forward, most of this story is somewhat on instagram, under #trucknamedsue Some of you already follow there, so if you are wondering this is the same build.

My goal is to have an early squarebody CCSB with a duramax, 4x4, and well executed and sorted to be able to drive it everyday- and anywhere in the country at a moments notice. I had a 2015 Denali Duramax truck and although it was nice, it got boring quickly. So the plan is that truck in a square shell, keeping all the original squarebody nick-nacks that make them super cool and improving where current 70's tech and GM fell short. @duramoose88's truck really was the final inspiration I needed to get moving. His truck-


Originally back in March 2017 I found a super cool truck on instragram for sale by a badass dude out in New Jersey. I knew better than to get a truck from there but I couldn't hold back. Truck seemed right, price was good, seller was easy to work with, and I wanted it. So I pulled the trigger- bought plane tickets and my buddy and I flew to New Jersey, grabbed the truck and drove back to New Orleans in 2 days. It was a great experience working on the truck at fuel stops, although quite frustrating and trying at times. I'd do it again though.

Truck was a 1976 camper special C20. 454/4speed. it had a previous restoration years back but seemed ok at first. it drove awesome, body wasn't perfect but it was something I could start with and drive while working on working my way to my end goal.

Some pictures of that truck and the trip to get it-

night we got back-




after a wash-




















It was a cool truck- but I found a little old lady who wanted it more than me. The excessive bondo and panel replacement made me tire of it quickly and when I received a really good offer I let it go. The lady wanted it to pull her tinyhouse which was the same color, I thought that was sweet. She never sent me pictures of it hooked up but I know it's done well for her.

About the same time I was selling the '76 chevy I found a '76 GMC. This was in June 2017. I was actually on my honeymoon and brokered the deal over facebook. My younger brother found the truck only 2 hrs away so it was too perfect. This truck was an original survivor, never touched. I don't know of any rust in it, but it is a little beat up. I decided this would be the body for my build. I haven't taken it apart yet, and have minimal pictures. I did drive this one home as well, during a tropical storm. lol.

1976 GMC Sierra Classic C35 with 10,000lbs title. 454/turbo 400. Has literally every option you could get in '76. It also has the correct early style doors which the yellow truck did not have- and bummed me out. So this was important. Also the colors are hideous and just perfect for the build, so I will be respraying it this factory brown/white. Note the white on the insert is not OE but resprayed soon after purchase.


bed is rough, but I won't use any of it.


While I was looking for the C35 and had the C20 I made a trip to Dallas TX to get some parts from a Texas Square Bodies. He has a good inventory of used parts, and is honest as they come.

I picked up a crewcab, fenders, bed floor and front panel, and some door panels and other little pieces. Later I went back and got a frame to cut on and also a super rare GMC tailgate. This allowed me to leave whatever truck I had on the road while I built a roller to swap the body on.

Frame was longer than my '18 trailer LOL-





So this is where the build thread basically starts. I ad the '76 GMC as my body, and plenty of extra parts to get started. I originally did a first round of fabrication to get all the bits I had at the time as far as I could take them while I continued to plan, plan, and plan the build. more on that later.

when I made it back with the frame I got it in the shop with the forklift and laid out the cut for the shortbed. Frame was decent shape, just had to cut off old homemade gooseneck and a few other brackets to clean it up-






frame cut and back together. took 14" out.




strength was a concern as I plan to use this truck to tow with a gooseneck when done. So I beveled and welded the inside first, then back gouged the outside and welded that up for a nice full penetration weld. I then used pieces that were removed and braced the inside of the rails over the cut. Not too much to cause stress risers but enough to support the cut area.













took 6" off the back. The frame had some random hitch welded on, so this was the best solution. I filled and moved the factory bumper holes and bed mounting holes.


test fit with some shortbed tanks. Got these from my buddy in Dallas as well.




cleaned up a bit more and frame was off to sandblasting/prime-


the radiator support also needed some rust repair before it was blasted and primed. I've since realized it's bent so I will need to fix that-




The tailgate I blasted, epoxied, blocked and filled and blocked, and polyester primed. It had been hit right on the M in the GMC but I got it all pulled out and put back right.


The final item I worked on in my initial fab push was the bedfloor. It was damaged from the original bedside removal so I fixed it up.











That's good for this first post. I'll continue the next chapter in a reply.

[phillipm]

Maybe resize the pictures down? They're so big I can't see them.

[RADustin]

Originally Posted by phillipm

Maybe resize the pictures down? They're so big I can't see them.

should be better. I really wanted to use dropbox to host as I pay for the service but it just wasn't going to happen. I have since moved everything to imgur.

[RADustin]

The idea of this truck originally started as wanting to build a crewcab 67-72. But I didn't want a custom body so I came to the decision to do an early square.

Before I purchased anything I did some decent feasibility studies to see if my plans would work, and if not how to modify them to work and fit/function.

Using a long bed frame drawing I found on the internet and a .dxf body I purchased, I got everything put in CAD. I'm a mechanical engineer by degree and design heavy equipment for a living, so it's second nature to realize everything in 3D CAD before a single piece of material is purchased.

Some of my earliest model progressions using stock square frame, 05+ Ford front D60, and LML Duramax rear axle, engine and trans. Original plans were coil springs in the front and leafs in the rear.



It can be noted that the LML radiator did not fit in the model and this proved to be true in real life.

I purchased a 2014 LML donor from copart out of Houston. Its about 60k miles, 4x4 with manual case. Involved in a flip accident but ran and drove once I welded the front suspension on it and got a key cut.




Out of the truck came the LML Duramax. Which is massive with twin EGRs. Designed and built a pallet to move it around the shop.




With the frame back from blasting/priming I went ahead and threw my extra cab on it, with some random front sheetmetal and coresupport. This allowed me to get some 3D scanning done and look at radiator options.

3D scanning the firewall-




fits the linesketch of the body perfect-


I knew the LML cooling stack was too large. But I wanted to try the LBZ/LMM stack. Luckily my brother let me borrow one he had.

LBZ/LMM compared to LML-


LBZ in the truck, obviously won't work. It'll have to be LB7/LLY-


Also realized with the scan it was going to be hard to fit the trans in a stock tunnel. I knew from research though that it has been done, but only in factory 4x4 trucks. So I sourced a tunnel, both the bolt in half and the weld in half.

Comparison-




I was able to put this data in CAD to place the engine/trans. Got the front suspension 4 link and front crossmember, engine mounts, and trans mounts designed. Steering bits was left on hold, as was coilover mounts. In the process of designing I went away from coils in favor of coilovers. Also will use air springs in rear with a level controller.

[RADustin]

Once the designs were solidified I went ahead and ordered all the material laser cut. This started the second major fabrication push on this project.

Much of the parts were broke on a brake I got from SWAG offroad. I modified it a little but it works well, especially for the price. There is also some machined DOM for the bushing tubes and machined aluminum bushing simulators to hold everything true while fitup and welding. Better than using the actual bushings.

Pallet of goodies-


Front crossmember, full of internal gusseting-














Internal frame stiffeners-




Trans crossmember. Made from 3x4x3/16" with some dimpled/broke plates-






Machined DOM for engine mount bushings.


Engine mount, engine sides mocked up-




The frame braces/engine mounts were tough to bend but came out nice-


had to make a little lower die for the press-


All the engine mounts-


Once everything was fabbed up I drilled a few holes and test fit everything. Dropped the engine in to check clearances. Fits well. Didn't put a cab over it yet but I'm hopeful it all clears. If not I'll cut the sheetmetal at this point.

[Dads79GMC]

That is some cool fab work!! Well done!

Mike

[RADustin]

This post should get this thread up to current. My end of year goal last year was to have the bed in primer. I used a used floor and front bulkhead with new LMC bedsides.

I want dual tanks, so I had to add the fuel filler to the bedside, it was fully tac'd before being ground smooth front and back-


The bedside fitment was terrible. I had to come along things into place to get a decent gap from the main bodyline down. Then cut off the flange on the upper tailgate gaps on both bedsides and remake to fit.


taillights didn't fit in their holes, had to cut the little tab loose and move it-




gap sucked-


front bulkhead had broken threaded tabs so I made some new ones-


but I did get the bed and tailgate final primed-




I finished designing the rear suspension. Using the 2014 AAM axle, Fox 2.5 shocks and firestone air springs. Late model Dodge 2500 application sway bar.

cleaned rear axle for new perches-




new perches cut on cnc plasma from 6x3x3/8" tubing. heavy stuff..




and stuck to axle-


modified B&W hitch from LML truck to work. Was too wide, u bolt spacing off from bed floor, and changed bolt pattern.




rear fox shocks-


started on rear gooseneck crossmembers. 2x3x3/16". slugged holes.






picked up Ford front axle-




finally, I deleted the EGR in the passenger up-pipe.







I'm currently waiting for the next round of laser cut parts for the rear to show up. Then fabrication part 3 will begin and last until the axles are under the frame and it's basically a roller. Then more design work on steering, front coilover buckets..etc.

[Indyfab]

Very impressive fabrication. Pretty jealous of the laser cut parts.

[Low Elco]

Great stuff! I gotta get me some CAD skills. It's bad when making stuff is the easy part, figuring out what to make is hard!

[RADustin]

Originally Posted by Dads79GMC

That is some cool fab work!! Well done!

Mike

Thanks sir!

Originally Posted by Indyfab

Very impressive fabrication. Pretty jealous of the laser cut parts.

Thanks! Laser is the way to go for sure. I have basic free access to CNC plasma and I still pay out the nose for laser. Totally worth it. P&O plate is also the trick.

Originally Posted by Low Elco

Great stuff! I gotta get me some CAD skills. It's bad when making stuff is the easy part, figuring out what to make is hard!

Man you say that! The better you get in CAD, the more tools you need/need access to. It's a vicious circle of spending money on truck VS spending on tools. It also makes a project very cyclic, where your working very hard- then stuck designing, then working again... but the integration you can achieve with CAD is unbelievable. When everything fits together and you took allowances from one part to fit another and everything lines up, it's pretty sweet.

[RADustin]

I bought a sweet grill from a member here on the site. Using it I designed some custom badges that I haven't cut yet but will cut later and have my sign painter brother fill in with color.

grill-


The GMC logo continues the center bar through it. and is a bit larger than factory-


Engine Badge-


kinda mocked up-


They should be neat. The GMC and engine badge have the upwards angle in them that the factory ones have. I'm waiting to get the truck together though to ensure the factory angle is good for seeing them based on the height. The truck will have about a 4" lift kit, on 35's/20's.

[aggie91]

Awesome thread. What CAD package are you using?

[RADustin]

Originally Posted by aggie91

Awesome thread. What CAD package are you using?

solidworks 2013. Been in SW since 2006.

[Flames97]

Wow!! Nice fab work!! Following!

[Devilman]

Wow again!! Very nice build!!

[SCOTI]

Very nice. Impressive work on the various brackets & pieces for the x-members. It's nice to know how to utilize design software & have access to certain equipment to bring your ideas to reality on an engineered level.

[RADustin]

Thanks Gentlemen. Should have some decent updates soon.

[STOCKISH]

Absolutely amazing. Can’t wait for more!

[COS399]

I'm jealous. This is an awesome build and can't wait to see it all done. I love the squares and like the ideal of mixing the old look with modern technology. Keep up the great work and keep us posted often.

[STOCKISH]

Wondering if you would have any interest in producing and selling those c-channel shaped frame stiffeners for us crew cab guys to bolt inside the frame where the 14” is taken out when we cut them for SWB.

[RADustin]

Originally Posted by STOCKISH

Absolutely amazing. Can’t wait for more!

me either! I need a crewcab back as a daily.

Originally Posted by COS399

I'm jealous. This is an awesome build and can't wait to see it all done. I love the squares and like the ideal of mixing the old look with modern technology. Keep up the great work and keep us posted often.

yep, I think so too. I'm retaining all the ABS, stabilitrak, integrated trailer brakes, and many creature comforts electrical wise from the donor truck. So it should be nice. It'll be neat to have onstar.

Originally Posted by STOCKISH

Wondering if you would have any interest in producing and selling those c-channel shaped frame stiffeners for us crew cab guys to bolt inside the frame where the 14” is taken out when we cut them for SWB.

probably. I'd need a little more info on exactly what you're looking for, and if 1 ton/crewcab, 3/4 ton or 1/2 ton.

[RADustin]

whelp, finally time for a decent update. Got my next order of laser parts in, wrong material but I used it anyways. I prefer to work with P&O plate but for some reason the laser shop thought standard A36 black plate was a perfect substitute.

so anyways, I used it all just cleaned it well with a scrubber wheel and alcohol before welding.

Pallet of parts-


all of these parts are rear end parts, so I started with the frame side 4 link brackets.

bent some metal and getting fit up, the aluminum bushing spacers are critcal-








bottom axle saddles bent and fit up. These have shock mounts and sway bar mounts integrated.-






upper bag brackets- also hold bump stops, upper shock mount and sway bar end link. started by bending out all these pieces-










machined the centering pins for the rear axle 4 link/bag brackets out of chromoly rod.


fitting up the axle side brackets-
















frame side brackets fitted-


inner stiffeners/gooseneck mounts-


gooseneck crossmembers. I really like how the transition/gussets worked out.






building out the 4-link and panhard. All the tubes are cut, faced flat, weld prepped, and drilled for plug welding. Quite a bit of work. They are tac'd up now, waiting for final welding until I am 100% on lengths.










with the rear end linked and sitting on the airbags, the engine and trans was able to be set back in to keep mocking/measuring and working with the CAD model.










so that's pretty much caught up to current. Just a ton of fab work, but making steady progress.

Will post some more in a few days.

[tinydb84]

Wow man. Just...wow.

[Devilman]

Soooo ummm when can I drop my 78 off for this same engine mount & suspension setup??? Lol but seriously I'd buy the entire kit from you if you wanna make a copy of yours.

Is there a big difference in widths between the 05+ ford axle and the AAM rear? I've been searching for a GM Dana 60 front axle but they're either junk or $1000+ still needing rebuilt. I've found loads of the 05+ ford axle with low miles for cheap and would like to use one of them.

[aggie91]

That's one heck of an update. Totally blown away.