1972 C20 build and adventure thread
 

Hey guys, I've been a member/lurker on here since May of 2013 when I picked up my 1972 C20, so I figured it was about time I tried to contribute some content.

I purchased the truck with the intent of using it as a daily driver, while also using it as an educational opportunity. I've worked on cars most of my life, but have never had the opportunity to rebuild entire systems on a vehicle. To that end, follow along as I post the past 6 years of ownership, upgrades, and adventures...hopefully in the next few weeks I'll have this caught up to the present.

As purchased in May 2013....1972 C20....paid $9500. Overall, a very nice example that was mostly stock, with one repaint. There is some rust in the typical spots (driver rear quarter, wheel well, etc), but nothing that I'm overly concerned with at the moment. When I retire from the Navy in 4 years and move to Texas, Ill probably pull the body off the frame and send it out to have the metal and paint work done, then reassemble myself. In the time being, I'm just enjoying tinkering and driving!

Re: 1972 C20 build and adventure thread
 

First summer of use in 2013....

Re: 1972 C20 build and adventure thread
 

Nice intro, FLYNAVY30...I'll be following intently! Your project seems very similar to where I'm starting (but yours seems a little nicer to begin with). Mine is a 1972 C/10 nine passenger which I have learned came with 3/4 ton suspension, but I'm still not clear on how else my C/10 differs from a C/20? Mine was originally powered by a 350 but had a brand new 454 installed in 1989 and also has front and rear air (but dealer installed)...both are involved stories that I'll share some day (if I start to make progress and do my own thread)! Thanks for starting your build thread as I really need the motivation!
Woody

Re: 1972 C20 build and adventure thread
 

Hey Woody, happy to help! I'd post more pics, but the internet out here is super slow at the moment. Mine was a factory two row truck with front and rear a/c along with the 402.

Greg

Re: 1972 C20 build and adventure thread
 

These are the first modifications I made to the truck, as well as some local parts sourcing for what I had hoped would be a relatively vanilla 5.7L LS and 4L60E swap....

The tires that came on the truck were pretty dry rotted. I decided that while I was buying new tires, I'd go up two sizes in order to better fill out the wheel wells while not making it look like a jacked up monster. I got a set of the 8 inch wide Ford steal wheels that accepted the factory hub caps. I painted them black for a little more subdued look as I always thought the white wheels looked too much like and ice cream truck.

Re: 1972 C20 build and adventure thread
 

The first real road trip in the new ride was August of 2013. I drove the truck from Norfolk VA up to Sebago ME for my buddy's wedding. I knew I was asking for trouble, but I brought tools and with the exception of a fuel pump change in Maine, and some under performing brakes, the truck did well. That being said, I was knocking down a solid 8 MPG from the tired 402. The looks I got stuck in traffic on the George Washington bridge going through NYC were priceless!

Re: 1972 C20 build and adventure thread
 

Count me in!

Re: 1972 C20 build and adventure thread
 

I really like the tire/rim size change as I did the same as you for the same reasons...Rotted tires and fill the wheel well! I went with 17x8 Ridlers wearing Goodyear Wrangler A/T Adventures.
Woody

Re: 1972 C20 build and adventure thread
 

Greg,
Family trips are what Suburbans are all about! I haven't had our's more than two hours from home-base yet...but I just retired, so I hope to do the same and put some distance experience on the odometer!
Woody

Re: 1972 C20 build and adventure thread
 

It really is the perfect road trip car. After I get out of the Navy in May 2023, my wife and I are going to take a 2-3 month "brake" and drive it from San Diego up to Vancouver with no real plan or itinerary....just exploring as we go. Then we'll drive back down to Austin and figure out the rest of our lives.

Re: 1972 C20 build and adventure thread
 

I started the initial tear down of the drivetrain in the fall of 2013. The goal was to have the LS/4L60E swap up and running, with a new wiring harness and functional A/C in time to drive it from Norfolk VA to Austin TX for our wedding in SEP 2014. It seamed like a reasonable goal...until a 6-month deployment to Korea popped up in December of 2013....

The initial plan was to use an aluminum 5.7L motor and 4L60E transmission I had found on Craigslist. To keep it simple, I used a Holley 650 carb, MSD ignition box, and FAST transmission controller. The new fuel system was all Holley stuff, while reusing the stock tank, which looked extremely clean and had probably been replaced at some point. The new wiring harness was from Painless, along with a vintage A/C unit and a giant Entropy radiator with dual fans to ensure no overheating issues in the future.

Re: 1972 C20 build and adventure thread
 

Anyone know how to rotate pictures??

Re: 1972 C20 build and adventure thread
 

Greg...I'm hoping you get an answer from someone with more computer knowledge than me, but I've been trying to rotate some of my photos as well! I have not found a "rotate button" even in the "advanced" section for posting. There is an "edit" feature for changing your post, but it still doesn't have a rotate feature that I could find. I tried posting a photo of mine that when I preview my post, the photo is upside-down...even though it shows correctly in my home album. I can rotate the photos from those albums so I rotated it to the upside-down position and tried to post it again. Same thing happened...when I previewed my post, it was still upside-down! DOH!!!
Woody

Re: 1972 C20 build and adventure thread
 

Love the Braves cap!

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Like this?
Attachment 1888667

Attachment 1888668

Attachment 1888669

Re: 1972 C20 build and adventure thread
 

Thanks! How'd you do that?!?

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My buddy's kid.....I'm from Boston

Re: 1972 C20 build and adventure thread
 

I really like the tire and wheel combo. Surprisingly (to me) the black wheels really look great. Im usually an ice cream truck wheel guy lol!

Re: 1972 C20 build and adventure thread
 

Greg...richard2717 helped me out with regards to this issue. It seems that photos taken with an IPhone commonly have these problems where photos taken with other cameras don't. As my home computer is a MAC, Richard couldn't walk me through anything specific, but he suggested that after I correctly rotated the problem photos, try saving them in a different location/album...then try to attach them to a post. It worked! Here is the photo I tried to share before that always posted upside-down. Rims are 17x8 Ridlers with 265/70R/17 Goodyear Wrangler A/T Adventures (31.6" tall). They fill the wheel-wells up similar to yours. I hope Richard's suggestion works for you as well!
Woody
Attachment 1892132

Re: 1972 C20 build and adventure thread
 

Thanks Woody, I did see your other post. Now that I'm back in the states, and have a decent internet connection, Ill try to get some more progress posts up.

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Glad you saw the post...and welcome back! My Nephew just left for Japan...also Navy. He has about 7 more good years to do, then on to the Sheriff's Department...if he follows suit with the rest of the family!
Woody

Re: 1972 C20 build and adventure thread
 

Very nice, love the dog too.

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More pics of the engine swap....

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Wife was super helpful.....

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V1.0 of the engine swap all buttoned up.... The unfortunate part is that shortly after getting the truck up and running, the bypass valve in the oil pump seized, bypassing oil back to the pan, resulting in multiple spun bearings. This was in the summer of 2014, shortly before we were to drive to Austin for our wedding.

At that point I was just frustrated, so I parked the truck and we headed to Austin.

Re: 1972 C20 build and adventure thread
 

Pretty expensive footstool....:)



That's a bummer for sure, after all that work. Hope you can get it fixed up. Keep on it.....

LockDoc

Re: 1972 C20 build and adventure thread
 

We got back from our wedding in September of 2014, after having our honeymoon cancelled due cancelled flights on the part of Delta, and incompetent call-center customer service on the part of Orbitz....side note, I'll never use one of those travel sights again. I decided to yank the wounded motor along with the tired junk-yard transmission I had originally used, and hunt for a long term, reliable replacement. I settled on a long block from Thompson Motorsports in Texas. They have an excellent reputation for a quality product on all of the LS forums. I went with a stock displacement, 6.0L iron block with a few upgrades like forged pistons, bigger cam, and some head work to bump the compression up to 10.5:1. For the transmission, I went with a Gear Star 4L65E STG 2.

While I was making such major changes, I decided to upgrade to the Holley Terminator EFI to run fuel injection, along with the ignition and transmission controller. In the first iteration of the build, I never felt like the engine and transmission were in sync. Shifts never seemed to be at the right time and the carb was very fussy to get started after sitting out overnight in the winter.

It took a while to get the truck back on the road, but I had it up and running in time from some later summer, early fall road trips in 2015.

Re: 1972 C20 build and adventure thread
 

After allowing the self-tuning EFI to learn for 1000 miles, I took it to VA Speed for a final dyno tune to smooth the fuel mapping by hand. The self learning EFI systems are really a 90% solution....they get you very close, but especially with an automatic transmission, having someone who knew what they were doing tweak the fuel and ignition maps, and a few of the shift points, made all the difference in the world. The truck drives like any factory equipped 6.0L LS truck. Through the end of 2015 and most of 2016, I put a fair number of miles on the truck. We drove Norfolk to Boston and then Maine again to visit friends, went up to Charlottesville, and then took the Blue Ridge Parkway all the way down to Asheville and back to Norfolk, then drove from Norfolk out to South Bend, Indiana to unfortunately watch Texas get destroyed by Notre Dame.

The one thing all of this road tripping did reveal was that the brakes needed to be addressed. The truck was factory equipped with front discs and rear drums, all of which were tired and needed work. I'm not particularly savvy on rebuilding drums, so I started searching for a viable disc conversion on the rear. More to follow.....

Re: 1972 C20 build and adventure thread
 

Really enjoyed this latest installment, Greg. Traveling is what my wife and I plan to do now that I'm retired...and the East Coast is on our "must do" list! The EFI and Brake enhancements are both on my wish list for down the road a bit...but I'm absorbing as much intel as I can before jumping into those projects. I'm actually impressed with how nicely the original brake set-up on my Suburban handles bringing this big truck to a stop...but there's definitely room for improvement! My 454 has a completely dialed-in Q-Jet (for sea-level), but as I plan on traveling to various elevations, the EFI sounds like the way to go. I currently have a 45 gallon vented tank that was dealer installed back in it's early years that I recently had out to change the sending unit. The tank is spotless inside and the outside was just covered in the normal road grime and dust from living in the desert for so long. I'd love to keep the tank, but do you know what would need to be done to utilize it? Thanks for the build thread...and I really like how you are integrating the "Adventure" aspect into the story!
Woody

Re: 1972 C20 build and adventure thread
 

Woody, I retained my stock tank as well, and used an external electric pump for the EFI with a return line going to the tank. If I were to do it again, I'd probably invest in an in-tank pump set up, but your stock tank can be modified to use those as well.....

https://www.holley.com/products/fuel...e/parts/12-130

In the case of the external electric pump, you need to ensure the pump is mounted as close to the tank as possible and even with the bottom of the tank. These pumps are designed to push, not pull. I found out the hard way that mounting the pump even with the lowest point of the tank makes all the difference in the world. I torched two pumps doing Rally North American in the Summer of 2017....more on that in a later post. In the mean time, below is a picture of my current set up. I fabricated the bracket which holds the inlet filter and pump in line with the bottom of the stock tank. There is also a "last chance filter" mounted on the frame rail up front, just prior to the line going up the fire wall to the throttle body. This set up has run flawlessly since 2017. If you have any additional questions about EFI, feel free to post them here. I can give you a pretty good run down on all of Holley's options, and the advantages of each. I used the "Terminator" on this application because you can get it with an ECU that will control both the engine and automatic transmission. When I swap my '64 Corvette to fuel injection, Ill use their cheaper "Sniper" system because the Vette has a manual transmission and will retain the stock style distributor ignition.

Re: 1972 C20 build and adventure thread
 

Thanks for the info, Greg...it brings to light how little I know about "modern" upgrades. I had "honed-in" on the Sniper because of the price differences, but now understand that I need to learn quite a bit more as the Beach-Burban is equipped with a stock THM 400 that has been recently gone through by a local transmission shop. For some reason, the "pedal mounted" kick down switch and harness were MIA, so I recently installed those...and man...did that wake-up this low horse-power big block (the heads have been redone as well, but they are "peanut ports") so I'll be keeping the trans! As I'm not ready to pull the trigger on this purchase yet, I'll continue to read and learn...and then get back to you with "intelligent" questions when I'm ready to start collecting the pieces! Thanks again!
Woody

No worries Woody! If youre going to retain the TH400, Id definitely go with the cheaper Sniper system as it retains a bracket for the old school kick down cable. I went Terminator because my 4L65E is computer controlled and one ECU running everything was a better option than separate ECUs for the EFI and trans.
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Re: 1972 C20 build and adventure thread
 

Well that's cool...being able to use the Sniper system! My kick down set-up is on the gas pedal and works well now...but it's nice knowing that if I ever wanted to go to the "carb" kick down style, I could. Yeah...the TH400 is a good transmission for a 3 speed. I'll have to keep my foot off the gas to try to compensate, although I've heard real good reports on EFI helping fuel economy...which is usually never spoken of in the same sentence as Big Block Chevy! I appreciate the help, Greg.
Woody

Re: 1972 C20 build and adventure thread
 

So as I stated earlier, I decided that I wanted to do something to improve the brakes. The factory set up wasn't terrible, but it wasn't great. I also wanted something more serviceable than the rear drums. What I came up with was a set of Wilwood's D52 replacement calipers for the front and rear. They are dual piston calipers as opposed to the stock single piston, and have different piston area front to rear to maintain the front to rear brake bias of the stock system. The fronts are direct bolt on replacements for the stock calipers. For the rears, I ordered a mounting bracket kit from (now out of business) Blackbird Customs. The kit used a custom bracket, and the front rotor from a later '78-83 K20. The installation was simple and straight forward...the axels did need to be removed from the stock Dana 60 in order to mount the rear caliper bracket, but that was only a two beer job. I used a 1 1/16 Baer master cylinder and bent up all new stainless lines, using braided stainless flex lines at all 4 corners and at the transition to the rear end. When it was all said and done, the only component of the brake system that was original was the pedal itself. Needless to say, stops are now straight and predictable. The only thing I would do differently is not use DOT 5 fluid. For just a driver application, it was recommended as it doesn't retain water, and will not harm paint if spilled. I have however found it to provide a slightly spongy feel when compared to a similar system using DOT 3. Its not terrible, and not worth the effort to completely flush the system, but something to consider for anyone contemplating a brake system rebuild.

Re: 1972 C20 build and adventure thread
 

The only downside to the new brake upgrade was that the aluminum Wilwood D52 calipers were just slightly larger than the stock iron D52 calipers....which meant the 16" steel wheels no longer fit. Unfortunately, period looking 17 inch wheels with the correct 8 lug pattern are pretty much non-existent. Everything looks like some gaudy piece of crap you would see on a new, jacked up GMC Sierra in the latest pop-country music video.

The least offensive wheels I could find were these American Racing Baja's in black. After getting the new BFG KO2's mounted, they've actually grown on me. I went up one more size on the tires to fill out the wheel wells as much as I could, again, without going to a lift. The new wheel/tire combo actually netted me an additional 1.5 inches of ground clearance, although the speedo is now off by 3 MPH at 60. While I was under the truck, I also replaced the shocks with a set of Ride Tech single adjustable units. They're a little spendy, but the ability to adjust the rebound added a degree of tune-ability to the suspension the helped improve the covered-wagon ride quality.

Re: 1972 C20 build and adventure thread
 

Glad to see the write up on your 'Burb Greg! Like your 'vette, it's a fine looking ride. I have the same wheels on my '02 GMC and we went with a similar one on my teenagers '72 Jimmy project. Sometimes all you can do is the lesser of all the evils!

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Agreed, after having them on the truck a while, I dont mind them at all. In a lot of ways, the point of this build was function over form so I'm good with them. They definitely dont add anything to the look, but I dont think they look out of place, or take away from the vintage beach truck look either.

If I ever get the chance to take this truck in the direction I'd really like to (aftermarket chasis, rust repair, new paint, etc) maybe I'll look into custom steelies that will accept the factory dog dish hub caps, but at the moment, that's not in the cards.

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Would be interesting to see what those rims look like painted body color with a chrome center cap.

But until they look old I’d just drive it!

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I was pretty sure I wouldn't like the new wheels, but they look pretty darn good. I think being black helps. Im surprised the calipers wouldn't work with 16 inch rims. No room to grind them down a tad?

BTW if you want I could ship you a Seahawks bumper sticker for your truck if you would like to cover the one some hooligan stuck on there without your knowledge haha!

Re: 1972 C20 build and adventure thread
 

I will be following this one closely. I am looking at a 72 Burb for a project, and this is right up my alley!

Very nice!