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.
Posted via Mobile Device

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!

Re: 1972 C20 build and adventure thread
 

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.

Re: 1972 C20 build and adventure thread
 

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!

Re: 1972 C20 build and adventure thread
 

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!

Re: 1972 C20 build and adventure thread
 

Hahaha....hard pass!

Re: 1972 C20 build and adventure thread
 

Thanks! Feel free to post any and all questions. I wish I had started this thread as I was building the truck....there would have been a lot more technical info about the process. Once I get the thread caught up to the current state, Ill cover all future mods in a little more detail.

Re: 1972 C20 build and adventure thread
 

The next couple updates will cover our week-long road trip in the Summer of 2017 on Rally North America. I highly recommend you look them up if you're into the road rally thing...there are some really good videos on youtube covering past years. My ONLY complaint (and this is extremely minor) is that I was surprised how few vintage cars were on the rally. Of the 72 teams that went, I think we were one of 5 cars over 20 years old.

Anyway, joining us on this adventure were my Brother and Sister In Law in his 1967 Camaro...which is another good story...he and I found that car the morning of my wedding. While everyone else was getting ready, we took the opportunity to go car shopping in and around Austin since you can't find rust free, vintage iron as readily on the East coast.

Also joining us were our next door neighbors in their Porsche Caymen S. The pics below are from day one as we drove from Norfolk VA to Charlottesville the day before the actual rally started.

Re: 1972 C20 build and adventure thread
 

Day two was spent driving from our over-night in Charlottesville up to Blacksburg for the start of the actual rally. We drove most of the way on the Blue Ridge Parkway which was absolutely gorgeous!

Re: 1972 C20 build and adventure thread
 

Very cool pics!

Thats gotta be the best lookin ls swap ive ever seen. Nice work!!!

Re: 1972 C20 build and adventure thread
 

Thanks! I've actually got a bit more tidying up to do under the hood. I bought a set of the old 327 finned valve covers with the "Corvette" script that I'm going to install using the LS to SBC adapters. I think that will complete the look with the chrome air lid and decal. I've also got some black braided stainless brake lines to replace the ones currently running off the master cylinder so that they aren't so "bling-y". Lastly, I'm still on the hunt for a radiator close out panel to fill the gap up front.

Re: 1972 C20 build and adventure thread
 

Day three was technically the first official day of the rally. We drove from Blacksburg to Danville, with a quick stop for a photo op at Martinsville, a mid day stop at a winery to keep the ladies motivated, and then some "hot-laps" at VIR. Yes, I did run two laps in the Suburban :metal: I was obviously extremely slow, but it ended up working out for our two compatriots as when I pulled off after two laps, the rest of the group was over half the track in front of us, still behind the "pace car" (which was driven by a professional driver, going about 6/10ths) so they got to run the rest of their laps pretty much wide open.

Re: 1972 C20 build and adventure thread
 

Day 4 took us from Danville, up to Grandfather Mountain, dinner stop in Asheville, and then finally into Waynesville NC. I wish I could get the panoramic photos from Grandfather Mountain to load properly, as they are pretty epic, but you get the idea. Those Wilwood brakes very much proved their worth crawling back down the mountain!

Re: 1972 C20 build and adventure thread
 

Day 5 of our adventure took us from Waynesville NC, through the mountains and to the official end of the rally in Rome GA. We got as high as 7000+ feet above sea level, which is of course where we encountered our only mechanical problem of the trip. I had noticed in the weeks leading up to the trip that my fuel pump would get warm, and start to wine a bit roughly 2 hours into a trip, but then if I stopped for gas, and let it cool off for a bit, it would be fine. I figured my brother-in-law's Camaro with 454 and a 4spd wasn't going to make it more than 2 hours on a tank, so I brought a spare pump and tools to be safe, but didn't give it much more thought. As I stated earlier, the problem was that I had the pump originally mounted on the rear cross member, which put it about half way down the tank. This mean that it was fine until I got below half a tank of gas, and then it had to work significantly harder to pull the fuel out of the tank. You can imagine how this scenario was exacerbated at 7000 feet, in the middle of summer. Fortunately, I managed to limp the last few hundred feet to the parking lot at the summit, where I swapped fuel pumps while the girls broke out some of the wine that had accumulated at various wineries along the trip. Obviously the new pump didn't permanently fix the problem, but after talking with the guys at Holley, I at least knew what the problem was, and made sure to top off before getting below a half tank. Its also worth pointing out at this point that the Holley Terminator EFI performed flawlessly the entire trip....including the elevation changes. The carb'd 454 Camaro did not appreciate the altitude changes at all!

Re: 1972 C20 build and adventure thread
 

Day 6 was somewhat of a bonus day....the rally was over, but the organizers were able to book laps at Talladega for anyone that wanted to run....of course everyone did, although the Suburban sat out due to the fuel pump, offload tires, high center of gravity, steep banked turns, etc, etc. I did get to ride shotgun in both the Camaro and the Porsche. The Camaro was awesome, and looked the part but was limited to about 110 MPH due to gearing and the 4 spd which meant we were barely fast enough to keep the car up on the banks of the track. The Porsche on the other hand was silly fast....and the faster you went, the more solid it felt. It just kind of hunkered down and kept gaining speed. Like VIR, these laps were "paced", but the lovely gentlemen driving the pace car certainly didn't appear to have any interest in limiting anyone's attempt at personal top speed records. We easily saw 150+ in the Porsche. After the fun at the track, we returned to Rome and spent that afternoon at the downtown beer garden....highly recommended if you ever find yourself in that area! All outdoor seating, right on the river.