1972 GMC K20 Dubbed "The Wilson Project" ***UPDATES***

[northfacetraveller]

Hey Guys,

I've been following the Expedition Portal for at least 10 years and love all the info and support! It keeps my dreams alive when I am unable to get out and explore.

I have finally purchased my dream truck! I found this truck on my way home from a doctors appointment one day sitting on the side of the road, covered in debris. I knocked on the door of the house it was parked outside of, made a deal with the owner and took it home. The lady i purchased it from said it was her late husbands truck and he had owned it since the mid 70's as he was the second owner. Unfortunately he passed away a couple of years ago due to cancer and she could no longer keep the truck. So I promised to give it the love it deserves.

My plans for this truck are fairly simple. I love the way it looks and prefer the vintage styling, so as far as appearance is concerned it might get some body work and a repaint, but most likely in factory colour combinations. I will install a GM 6.0 LS power plant and matching 4l80E transmission and adapt the current NP205 Transfer Case. Keeping in mind that I want to use this truck as a daily driver when I feel like it and take it out camping, reliability is key. The modern fuel injection and power, reliability and easy access to parts is the reason i have decided to go with this power plant. I plan to upgrade the suspension system and steering as well. Longer leaf springs, and possibly custom made leaf springs will be on the list depending on overall cost. Crossover Steering is a must as well as a tighter ratio steering box.

Once the build is more or less completed, i plan to run an 8' Pop Top Camper on it so we can do some Overlanding and occasionally tow our Jeep down to Moab and or Rubicon for some wheeling trips. I'm super stoked for the build, can't wait to get started! Keep in mind, this will be a fairly budget build, I will spend the money where I feel it is necessary but this will be a modest build. I do not have sponsors, nor any help financially so this will take some time as I save up the money to get'er done. Really hoping to have it out on the trails next Summer/Fall!

Hope you enjoy the build process, feel free to offer any advice if you feel I could be doing something better as the process evolves.


Instagram @dirtroadconceptz

 

[gnel]

Wow! Nice find. I used to own a 1972 C20 4x4 manual 4 speed with the gas guzzling 350 v8. Great memories of that truck with an Alaskan camper in Baja. I had saddle tanks installed for more range. The thing was a tank!

 

[northfacetraveller]

Just finalized the deal for the motor! Its a 2005 GM 6.0 LQ4 with 262,051 on the ticker. It is mated to a 4l80e transmission and what I believe is a NP261 Transfer-case which I will determine once its in my possession. I got to drive the truck around the farm for a few minutes beforehand to make sure everything is good. Only problem I noticed was the oil pressure gauge was pinned, but I know its common for those gauges to fail like that. Either way, I decided to jump on it for the price and take the gamble. If only I had brought my little scanner I could of checked, oh well cross my fingers! Will dig into it when I get it home in a couple of days. First I need to make room in my tiny garage!

 

[borison]

Best GM body style ever. Looking forward to this.

 

[dixie1865]

beautiful truck.

 

[Halligan]

Lets see some more pictures of that truck.

 

[Martinjmpr]

IMO the 67-72 line was the best looking GM/Chevy series ever.

The only thing that would have made this more drool-worth were if it was a 3 door Suburban!

 

[vargsmetal]

Beautiful truck. Are you planning on reworking the harness yourself, sending it out to be reworked or buying your own? I've done a 5.3/4L80e myself if you have any questions.

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[northfacetraveller]

Alright, so today my wife and I loaded up with some tools, picked up a U-Haul Trailer and headed west to pick up the new drivetrain for Wilson. It was a bit of a pain in the ass due to the fact we live in a townhouse because our ridiculously expense real estate market here in Vancouver, BC. So needless to say, my neighbors think im ridiculous for putting this amount of effort into a "Old Truck" haha. Anyways, the motor is decent, came out of a 2005 Sierra 2500HD with 262,000kms on the clock. I was really hoping for something with less mileage, but the deal was right at $1600 for the entire drivetrain so we made it happen. The motor is a little crusty on the outside, but ran good and drove good as I was able to drive it around the guys farm before making the deal.

Had to stop at a buddy's house quick to pull the transmission off from the motor so I would be able to pick it up with the cherry picker (that i also had to pick up on the way home). Some good laughs and a few bolts later we had the transmission removed and we carried on back home. Realistically considering my OCD I will probably tear the motor down and have it sent to the machine shop and checked for wear, cracks etc.. Once all is good, Im thinking I will install new crank bearings, cam bearings and piston rings. I feel this will give me some piece of mind in the long run. In time I will tell once i rip it apart. Hoping to find some shop space locally that I can rent, would make the process a lot simpler.

Vargsmetal - I am leaning towards running the Holley Terminator X management system, seems like the best bang for your buck. I like all the features it has and that its canbus. Less wires cluttering the engine bay and self tuning is a major bonus! I have thought about reworking the old harness, but i honestly don't feel like thats the best value for my time. I've also checked out aftermarket harness's from painless, psi anda few other smaller harness builders but they all appear to run around the 600-700 range, then i would still need to get the VATS deleted and a tune which would cost another few hundred providing the tuner is good. So thats really my reasoning behind the Holley System.

Will try to get some more pictures of the truck! I've honestly only had it for a couple of months so I don't really have any good pics of it. It just sits in the garage waiting for surgery! Probably won't be able to do much for a couple days as ill be busy with work and some stuff around the house. But as soon as I get more done I will definitely share.

 

[vargsmetal]

The Terminator is a great system. However, if you won't be needing the advanced features for tuning and racing, and if you're sticking with a basically stock engine I don't think its necessary. I reworked my 5.3L harness in an afternoon following LT1swap, and used the Bussman RTMR fuse/relay box. The GM pcm is very powerful and pretty much any dyno shop can tune it for you if you are doing and upgrades like a cam. Using hptuners you can also tune it yourself, it's just not "self-tuning" like the holley setup. Mine is completely stock so I just had LT1swap remove VATS and emissions, and replace the transmission segement for $75.

Matthew LS Harnesses on facebook does quality work reworking factory harnesses if you don't want to do it yourself. Just another option.

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[ExpoMike]

Cool truck! Not sure if you noticed or not but the transfer case on the newer setup is a driver side drop and your front axle is a passenger side drop. Those are not going to work together. GM changed the front output side when they went from solid axle to IFS.

 

[rkj__]

Great looking truck.

Being born in the late 80s, I never paid too much attention to the trucks from the early 70s. But, I bough an RC rock crawler with a '72 K10 body on it, and now these trucks always catch my eye when I pass one. There are not a ton out there getting used, that are in as good condition as the one you found. Enjoy your truck, and stay safe when you take it out on the road.

 

[zoomad75]

That is a really nice GMC. Great bones for a project for sure. Get to know ORD, Off Road Design. They are the experts in GM solid axle suspensions. Plus they have other items that would help facilitate the swap like the high clearance engine cross member and LS engine mounts.

I'd recommend ditching the in-cab fuel tank as part of your swap as well. It can be made to work, but I'm not a fan of having it inside the cab. A very popular way to go is using a K5 Blazer tank out back behind the axle. You'll lose the ability to carry a spare down there, but you can mount one inside the bed or build a swingout carrier on the bumper. Bonus to this is using a TBI tank and sender that would make it ready for the LS swap. Use an EP381 AC Delco pump instead of the TBI pump and you'll have all the fuel you need to run the 6.0. The Blazer tank is 31 gallons too, so you'll get decent range too.

I'd be on the look out for a FourWheel Pop-up Grandby for the bed of that truck. It would drop right in and fit with the gate closed. But I might be getting ahead of the game. Get the swap done first!

 

[vargsmetal]

That is a really nice GMC. Great bones for a project for sure. Get to know ORD, Off Road Design. They are the experts in GM solid axle suspensions. Plus they have other items that would help facilitate the swap like the high clearance engine cross member and LS engine mounts.

I'd recommend ditching the in-cab fuel tank as part of your swap as well. It can be made to work, but I'm not a fan of having it inside the cab. A very popular way to go is using a K5 Blazer tank out back behind the axle. You'll lose the ability to carry a spare down there, but you can mount one inside the bed or build a swingout carrier on the bumper. Bonus to this is using a TBI tank and sender that would make it ready for the LS swap. Use an EP381 AC Delco pump instead of the TBI pump and you'll have all the fuel you need to run the 6.0. The Blazer tank is 31 gallons too, so you'll get decent range too.

I'd be on the look out for a FourWheel Pop-up Grandby for the bed of that truck. It would drop right in and fit with the gate closed. But I might be getting ahead of the game. Get the swap done first!

I wonder if a 96+ GMT400 or GMT800 tahoe/suburban tank would fit back there. Would already come with the right fuel pump. The 1996 fuel pump housing works with the old guages, and is what I used in my swap to feed a 5.3L. I believe they changed the element for 97+

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[1stDeuce]

This looks like a great project!
With only 262k Km on it, that engine is barely broken in. If a compression test shows good on all cyls, I'd run it. I put a new timing set in my '02 6.0l thinking the original was a bit sloppy. The new set made no difference. Run it.

FWIW, I don't think the 2500/3500 trucks have any sort of key security... (VATS) I know neither my 2002 or 2006 do...
<edit> I stand corrected. It's PASSlock, which doesn't use a special key, but rather a special lock cylinder. So long as you turn the cylinder with a key, the security system allows a start. You may indeed have to reflash the ECM to remove the security feature...

I've had good success reworking factory harnesses, but there are several places selling relatively inexpensive standalone harnesses that might make it less painful. (Search "6.0l swap harness")
My experience has been that you won't find an aftermarket EFI setup that works as well as the factory one, and the factory setup also controls the transmission, which makes the two work well together. If you go aftermarket on the engine, you'll also have to go aftermarket on the trans...