78 C10 to K20, aka "The Green Truck"

[VanceOnTheInternet]

Hey everyone! I have been an occasional lurker for a few years here, but never signed up. I have now undertaken a big project, and I am bound to have questions. I figured a build thread would help me keep track of what I am doing, and maybe save everyone the trouble of having to read an explanation of my plans every time I have a question. Oh, and help me show off a bit! A little about me first though: I have been a gear head since I can remember, but my formative years were spent lusting after mostly imports in the late 90s. I have had quite a few vehicles, everything from Monteros to Miatas, but most of them were sporty, small, and Japanese. I am sort of new to Chevys, small blocks, carburetors, leaf springs, etc. My father-in-law is slowly converting me, but forgive me if I don't have all the lingo figured out yet! Also, I tend to be long-winded...

About 5 years ago, my father-in-law gave my wife and I a really nice 1978 C10. He didn't want to sell it, but had little use for it anymore. I was more than happy to take over stewardship over what I saw as a family heirloom. The truck has been in my wife's family almost since new. My father-in-law bought it in 1982 from the original owner's widow I believe. My wife actually came home from the hospital in it. It was the family vehicle for a few years, until more children came into the picture and necessitated the moved to a Suburban.








The truck has been through many iterations under my father-in-law's ownership. It was originally a heavy half with a 350 and a th350. At some point my father-in-law swapped a 454 into it, before putting a worked over 350 back in. He put the 15x10 turbine wheels on and had the bench reupholstered and swapped in a 3.73 rear end. It was originally a two tone green, but sometime in the mid 90s he had it painted a metallic green and all the trim running down the side of the truck removed. He also had the body guy put standard mirrors on it in place of the larger towing mirrors. Mechanically, it has a rebuilt trans and the front end was all replaced in the 90s as well. It has a great 350 in it. It's got an estimated 10:1 compression, later vortec heads, an Edlebrock intake and carb, and a mild cam. I believe it has flat top pistons. I don't know the specific cam, intake, or carb, and my father-in-law doesn't remember. From my limited research, it seems like that recipe could be good for 350hp, but maybe you guys can tell me more. It can get out of its own way for sure, but needs some tuning. I will need to learn to tune a carb and distributor!

Currently, it looks great from 10 feet, but has a few bruises when you get close. The bench needs reupholstered again. It's not a show truck, but drives great, gets lots of compliments, and has proven very reliable. It has only needed a battery, wheel bearing, and oil changes since I have had it. It now needs new tires and some other odds and ends.

My father-in-law had a bit of a sport truck vibe going with the turbine wheels and 275/60 tires. Now that I have taken over stewardship of the truck, with my FIL's blessing, I'm transforming it into more of a classic work truck and converting it to 4WD. I have lots of reasons (*cough* excuses *cough*) for doing this, but it all started because I just missed having 4WD around, but I consider the truck a family heirloom and I don't want to part with it! My wife is very accommodating, but I would have trouble justifying a 4WD SUV or pickup AND the C10.

So, in order to have my cake and eat it too, the Green Truck (as it is known by everyone) will become a multipurpose vehicle. It will be a 4WD camping/exploring rig, a classic project vehicle, family heirloom, and truck for hauling things (like my rallycross project) when needed. I have a 2.5 year old daughter, and I have visions camping and fishing with her in the next year. Another bonus of this plan, I also don't have to give up my sporty daily driver.

So with all that background, on to the project part: A few months ago I purchased a 1980 k20 with an sm465/np205 and a 350. Let me start off by saying it was super cheap, and I feel that is important to remember before I start describing it. I picked it up for $500. The body was rusty and full of holes, the floors were being held together by three layers of floor mats screwed into areas of solid metal, the carb (at least, if not the heads as well) was full of water, and it had a 2" or so lift cobbled together with square tubing "blocks" in the front and "ambulance" springs in the rear. The previous owner couldn't find the keys or the title. I'm pretty sure the truck had sat for close to a decade, judging by the sticker on the license plate.







On the plus side, it had 4 straight factory 16" steel wheels with hubcaps that are mostly free of dents. Which is good, because the end goal is a mostly factory looking truck. It also had the 10.25in FF 14 bolt and the big drum brakes. The trans shifted well and the axles didn't have any obvious leaks or issues. In the end, it was cheap and seemed perfect for my plans, so it went home with me despite its numerous issues.

Actually, it sat at my brother-in-law's house for a month or so first! His wife was thrilled.



Because my father-in-law has a huge shop and I only have a small spot next to my garage, much of the work will take place there. My wife's family all live a few hours away, which complicates things a bit. So the was to first remove the body, engine, trans, and transfer case of the K20. My father-in-law, who has a truck and trailer and is retired, will then deliver the rolling chassis to my house, where I will clean it, paint it, and do anything else I can to prep it for the next stage. At that point, it will travel back to his house where we will merge it with the body and engine out from the Green Truck.

[VanceOnTheInternet]

Continuing with my saga, back in January my FIL (I'm going to use that from now on because I am sick of typing father-in-law) and I tore into the K20 over a weekend. Out of the entire body and interior, the only parts I pulled off that weren't rusted, tweaked, bent, cracked or otherwise rendered useless were the headlight surrounds. Literally everything else was garbage. Actually the rear bumper will be reused, after getting cleaned up and a coat of paint. There was some salvageable parts off the engine, but it was completely locked up. We didn't spend too much time messing with it.

The mostly bad things I discovered:
Unsurprisingly, the front end needs rebuilt. The lines to the steering box were disconnected and the it was full of water. All the balljoints long ago seeped out all of their grease. The draglink is bent. Moving rearward, the front driveshaft u-joints had no needle bearings left. There is enough mud caked to axle housing, transmission and transfer case that I can't make out their true shape.

The bed used to be painted red. Another interesting thing I discovered was that while right tank appears to be the original 20 gal tank with a steel skid plate, there is no filler on that side of the bed. The left tank is a 16 gal tank, which weren't offered on long beds, correct? I am guessing the left side got hit at one point and the bed and left tank were replaced in the cheapest possible manner.

The rear "ambulance" springs were just set on the axle, the stock springs set on top of those, and it was all bolted together with homemade plates and u-bolts. I bet this thing rode like a dump truck.


The obviously professionally installed rear springs

The worst discovery of the day was mud-filled front spring hanger on the right rear. While digging the mud out of it with a screw driver, I was able to poke a hole in it. Mud sitting in it for year apparently rotted through. So that will need replaced. Luckily, the rest of the frame is very solid. Overall, the spring hanger was the only thing that was unexpected. Everything else is either coming from the Green Truck or I was planning on replacing anyway.




You can see the 20gal tank and lack of filler on the bed. And the red paint.



And now last week, the chassis was delivered to my house. You guys are now all caught up with my project/life story. I know I will have a ton of questions.

[VanceOnTheInternet]

I still don't know what know what gears are in it, and I don't know if it has a LSD or locker in the rear. The tag with option codes on it is no where to be found unfortunately.

The plan is to lift it 2in or so and run 255/85r16 (roughly 33x10.5) BFG KM2s when the time comes, for classic work truck look, but slightly beefier than stock. I still researching the best way to get the lift I want, but I am leaning towards ORD shackles in the rear and the Ez-ride springs they offer for the front. I think one of the rear spring packs (the stock springs that is) has at least one broken leaf, so that will need to be addressed. More as I get time to tear into it.

[VanceOnTheInternet]

So I need a front spring hanger for the right rear spring (that's a confusing sentence). I seem to be able to find them for reasonable prices for 2wd trucks. I have only found one source for a 4wd hanger and it was over $100 (and that doesn't include hardware I believe). Any suggestions on where to look?

[bustin dailey]

Thanks for sharing!

On a selfish note... I see that you are going for a stockish look, etc etc... That leads me to believe those 15x10 turbine wheels may be up for grabs at some point!

I'm in mid missouri, and my dad near Branson, so I bet we could work something out if you are looking to get rid of them.

Let me know!

Also, good progress so far, keep it up!