1968 GMC - Ol' Blue

[MDPotter]

Hello everyone - I've been on the 60-66 forum for a short while as my dad and I near completion on his 64 C10 restomod. I've always liked the 67-72 body style and I picked one up a couple weeks ago. Driving it is nostalgic for me because I grew up on a farm and I worked the summers helping with grain harvest and the trucks we used to haul grain are 68 Chevys (still in use today). I'm still young, but those days are 10 years behind me now.

My coworker bought this truck from what appears to be the second owner. The first owner put 11,000 miles on it from when it was purchased until 1988, then the second owner put 23,000 miles on it between 1988 and 2017. My coworker (third owner) put less than 30 miles on it in the past year (now over 34,000). It's a 1968 C15 longbed with a 327 and 4-speed manual. From what I can tell, everything but the seat, dash cover, and wheels/tires are original.

My coworker put block-hugger headers on it, but the headers weren't made for the truck as evidenced by the hammering of a couple tubes and the fact that the collector pointed at the starter. I believe the second owner put the wheels on it and my coworker put new tires on it.

Here's what I've done to it so far:
-Put the stock exhaust manifolds back on and put a couple Thrush turbo mufflers on
-Replaced the tail light, reverse light, and side marker lenses
-Registration and plates
-Polished what paint is left

Short term plans:
-Replace the heater core and get the heating system working
-Get the headlights working

Long term plans:
-Full on restomod - shortbed conversion, lowering, new wheels and tires, LS swap, etc.

The truck runs great and I don't have the time to get into the restoration yet, so I'm planning to drive it for awhile and tear it apart this winter or next spring. I don't know why the engine bay pic is upside down, I've tried flipping the picture on my phone and on the computer before uploading and it still comes out upside down.

[MDPotter]

It's been awhile since my first post - my dad and I have been working on his 64 and it's taken a lot longer than we anticipated and we only work on it one day a week. But all of the systems are done - fuel, brakes, cooling, steering, and wiring. Now we have to put all the front body panels on and load the doors.

As far as my 68 goes, I've been slowly working on my LQ9. The harness has been stripped of all the unnecessary wires/connectors, power wires merged, re-loomed, and PCM reprogrammed which is as far as I can go with it until I get it in the truck. I've really enjoyed that process - it's rewarding to do the rework yourself and couldn't have done it without Brendan at LT1Swap and all his info. Hopefully when I go to start it everything works! If not, I can always buy a harness.

I bought the LQ9 out of an 04 Escalade from a dismantler in New Hampshire and it's got quite a bit of rust and corrosion as you can see - I think they took the hood off it and let it sit out in the weather for at least a year. According to the seller, it only has 111,000 miles on it and I did find the salvage listing with the VIN they provided me and the mileage matches. Being a "trust but verify" person, I pulled off the manifolds and spark plugs and was able to shine a flashlight in to see the flat top pistons and I can even see the writing on them (they're that clean), so I feel pretty good about the engine. My initial plan was to rebuild it, but in the interest of budget and considering the condition of the engine, I've decided to replace a few parts and drop it in with the internals as-is. I've got it pretty well stripped down and a power steering pump (with 2 returns for future hydroboost), water pump, Speed Engineering headers, Speed Engineering engine plates, idler pulley, tensioner, starter, 4L80 flexplate, and rear brake rebuild kit on the way.

For anyone considering going the route I am - buying the engine separate from the transmission and going the "value" route - you get what you pay for. My dad chose to spend more on a complete dropout all aluminum Gen IV 5.3 with a 6L80 and it's immaculate compared to my LQ9. I've had to replace a few connectors that were damaged in addition to the parts I listed above. It's also got a lot of rust, corrosion, grease and grime on it. Going the route that I did will nickel and dime you every step of the way and take up more of your time, but it will save you money overall. If you want a complete dropout in excellent condition, you have to pay more.

I finally got a sport bumper put on as well. If you're buying repop brackets, make sure the ends of the inner brackets that attach to the bumper are flat so that when you tighten the bolt it doesn't damage your bumper. I got this heads-up in a bumper bracket thread and was able to heat up the portion of the bracket that had a bit of a curve to it and flatten it out and it worked just fine.

I'm hoping to finish up my dad's truck in the next few months so we can tear into mine. I've taken all the lessons learned and time up front to research all my ls swap parts so as to get the best value. I'll be ordering a reman 4L80 this month and at that point I'll have all the parts I need to mount the engine/trans to the truck. Just need more time!

[cornerstone]

Your dads 64 looks laser straight and beautiful. I guess blue is the family color! Thanks for the reminder on the rear bumper brackets possibly jacking up a new bumper. I'm getting close to that stage and knowing me, well, I'd have a dented bumper...

[MDPotter]

Originally Posted by cornerstone

Your dads 64 looks laser straight and beautiful. I guess blue is the family color! Thanks for the reminder on the rear bumper brackets possibly jacking up a new bumper. I'm getting close to that stage and knowing me, well, I'd have a dented bumper...

Thanks! We ended up buying a whole new bed because the old one was too rusted and damaged to be salvaged (at least with our skill set). I was thinking about painting my 68 red, but people keep telling me how much of a target it will be.

[MDPotter]

I got the accessory drive complete - new water pump, tensioner pulley, idler pulley, power steering pump and pulley, and belt. I sandblasted the alternator/PS bracket to get the corrosion off and it looks decent.

I also test fitted my speed engineering headers and engine plates. The headers look great and my plug wires just clear in a couple spots. I couldn't attach the plate on the driver side as the lower front corner was hitting a ground bolt so I need to grind that tip a little bit.

[MDPotter]

LS1Nova's build threads inspired me to take the time and clean and paint my engine. The engine had a lot of grease, oil, and dirt on it and the block was rusty so I took it apart Saturday to clean and paint it. I pulled a valve cover off and the heads looked good.

I bought a needle scaler at Harbor Freight to clean up the block and it worked well. I also sandblasted the block and timing cover in prep for paint. The remainder of the engine was treated with degreaser and scrubbing and looks much better. I also painted the power steering/alternator bracket and tensioner. I didn't have a lot of time Sunday, but was able to get the bed off.

Next weekend I hope to get the engine and trans out so I can sell them and get the front end apart.

[MDPotter]

[MDPotter]

We made a lot of progress Saturday-we pulled the the rest of the body, engine and trans out. Also discovered that the engine is actually a 307, not a 327. Next steps - frame shortening and disassembling front suspension to get the chassis ready for the sandblaster!

My dad and I decided to take a picture with all of our trucks a couple weeks ago as it was the last time for awhile that they will all be complete. My 2016 and 1968 and my dad's 2006, 2003, and 1964. I drove the 2016 in high school and he decided to keep it and his Sonoma has been his daily driver for about 15 years. He was about to sell it as he's now driving his 64 every day, but he had second thoughts and wants to LS swap it after we finish my truck!

[MDPotter]

Last night I did what I should have done when I last had the engine apart and replaced the knock sensors, harness, and intake manifold gaskets. There was a lot of gunk down in the recesses and they were both pretty corroded. I didn't stop to take a picture, but I did the RTV dam around the rubber stoppers at the knock sensors. I also started the frame shortening process by cutting 8" off the rear. Hopefully I can finish the frame shortening this weekend.

[MDPotter]

Frame shortening is complete. I recycled the cut sections as fish plates on the inside. We cross-checked for square and it was within 1/8" so I'm happy. I also removed the manual trans crossmember, clutch linkage bracket, brake lines, and fuel lines.

Next weekend I should be able to drill for the rear cab mounts, pressure wash the chassis, and finish taking it apart so I can take it to the sandblaster.

[dagnabbitt]

Pretty neat cuts and welds, I wish I had the guts or the skill to do that. No template, no kit? Have you done that before?

[MDPotter]

Originally Posted by dagnabbitt

Pretty neat cuts and welds, I wish I had the guts or the skill to do that. No template, no kit? Have you done that before?

I've been cutting and welding for years, but this is my first frame shortening. I looked at the Brothers kit, but essentially you're paying $300 for a template that for sure makes it easier but isn't necessary if you've got the cab off the frame. I've watched several videos and went through several build threads to see this done and it's not that complicated. Measure 5 times, cut once, take your time. I cut a little bit inside the marks and then used a grinder to sneak up on the cut lines for a tight joint. Bevel the edges and crank up the heat on the welder to get good penetration and fishplate the inside. Remember, it's just steel and this isn't a Lamborghini.

[MDPotter]

Finished disassembling the chassis Saturday and dropped off at the sandblaster. There was about a 2" thick buildup of New Mexico sand, grease and oil around the ball joints. It was a workout removing the old cross shaft end caps - had to use a 16" crescent with a 4' cheater to loosen them. Sorry for the sideways/upside down pics, I don't know how to fix it. I've tried flipping them on my phone and they still don't come out right. It must be the way I hold the phone when I take the pictures.

[cornerstone]

Originally Posted by MDPotter

I've tried flipping them on my phone and they still don't come out right. It must be the way I hold the phone when I take the pictures.

Yes. I know how to correct the problem (if you are using an iPhone). Hold the phone sideways so that the home button is on the right side.

Nice work. I agree with you, no need for the Brothers kit. Just read up, measure 5 times, cut it with room to spare and creep up on the exact line with a grinder. Save the $$$!

[MDPotter]

The sandblaster is pretty backed up, so I didn't get any parts back last week and I might not this week either. But progress is progress, even if it's not the order I planned on. I was able to spray chassis saver on all of my new chassis parts - steering gear, pitman arm, idler arm, cross shafts, and spindles and I also painted my calipers. The engine and trans are mated together and I have one door emptied. randy500's post on door disassembly/reassembly is a good writeup - I did the disassembly in that order and it went great.

I'm really hoping my sandblaster can get to some or all of my parts this week, but not crossing my fingers.

[MDPotter]

Saturday we got quite a bit done. I decided that I want to mount my PCM and TAC module in the cab, so I laid out my harness, pulled the loom and tape, and rerouted wires so I can have one bundle running down the top of the transmission and I'll bring them up underneath the seats. I'll be spending some time in the evenings lengthening and shortening the wires back to the PCM connectors to clean up the spaghetti mess of wires I have now. I think what I'll have to do is label each wire for its position in the connector and pull them all out in order to sort out this mess.

We also deskinned both doors so I can take them to the sandblaster with the next batch of parts. The cab is also stripped and I'm ready to start closing up holes in the firewall, floor, and a few other spots (spotlight hole in driver's side pillar, gun rack mounting holes).

I ordered a BTR Stage 2 truck cam and springs last week so next weekend I will be swapping that out with new valve springs. My sandblaster still hasn't touched any of my chassis parts and the weather here isn't helping.

[MDPotter]

Got a lot done this weekend. Cam/spring swap (BTR Stage 2 Truck cam) is complete and chassis is painted and almost a roller again. I wanted to get the spindles and rotors on, but ran out of time. I am going to focus on bodywork now - I'm going to get as much done as I can on the cab, doors, hood, and fenders before October. I'd love to have it all painted by October so I can work on assembly, wiring, and finishing the chassis when fall comes, but it's a pretty aggressive goal considering how busy my summer will be.

[MDPotter]

Another productive Sunday - finished assembling the front end, set the engine/trans on the chassis, test fit with the cab (plenty of room), set the core support, installed the headers, and fabbed up a trans crossmember and painted it. I'm very pleased with how quickly and easily it's coming together - my dad and I learned so much on his 64 and the 67-72's are more user friendly.

[MDPotter]

Got a little bit done yesterday - trans crossmember is bolted in, shocks are in, and filled all the unneeded holes in the firewall.

I'm hoping to get a driveshaft this week as well as some panels back from the blaster so I can prime next weekend and continue filling holes in the cab.

[TA_C10]

Nice work man. I'm subscribing. Couple questions:

1. DBW or DBC for the LS? Where/How are you mounting the pedal?
2. Are you painting your core support or leaving it just e-coat?
3. 2 piece driveshaft or single?

Looking good man, keep it up!

[MDPotter]

Thanks man, I've been watching yours too.

1) DBW. I was looking at another build (1971Stepside - post 27) and he had used the stock LS pedal assembly and welded in a plate with a couple nuts to the firewall and I am going to look at doing that. I've seen the adapter plates but they seem so bulky and I've already welded shut my gas pedal nuts. I help up my gas pedal the other day and that spot seems to put it in about the right position. I have the same pedal (adjustable pedals came in Denalis and Escalades) and it's really bulky, so I might try modifying it so it's not such a monstrosity and since the adjustability function is no longer usable.

2) Core support was blasted and it has Chassis Saver on it. It's basically epoxy and it dries to a satin finish. I put it on my frame and all my chassis parts. It's nasty stuff, it takes forever to get it off your skin, but it sticks to almost anything. It's a competitor to POR15 so it sticks to rust too.

3) It's a one-piece driveshaft made locally by a driveline shop.

[TA_C10]

Thanks for the info! And funny i'm in same boat with pedal. I already welded up the original nuts in firewall... Check out what this guy did with his. Although it doesn't show how he mounted it to firewall, I was planning on modifying the pedal like this to get rid of the adjustable stuff. Then I will probably do the same as 1971Stepside to mount it to firewall.

Pedal Idea:
http://67-72chevytrucks.com/vboard/s...2&postcount=18

[MDPotter]

Originally Posted by TA_C10

Thanks for the info! And funny i'm in same boat with pedal. I already welded up the original nuts in firewall... Check out what this guy did with his. Although it doesn't show how he mounted it to firewall, I was planning on modifying the pedal like this to get rid of the adjustable stuff. Then I will probably do the same as 1971Stepside to mount it to firewall.

Pedal Idea:
http://67-72chevytrucks.com/vboard/s...2&postcount=18

I saw that one too and forgot to mention it, that's a cool mod. I have to spend some time with it and mount the brake pedal bracket and pedal temporarily to mock it up.

[MDPotter]

Doors are epoxied, driveshaft is in, and I'm done reworking my LS harness. I spent hours and hours working on this harness and I'm pretty happy with it now. I initially just pulled out all the unncessary wiring and reloomed it, but then I decided I wanted to mount the PCM in the cab so I ended up shortening or lengthening pretty much every wire back to the PCM connectors. I didn't want to have the LS power wiring made up in the engine bay, so I bought an American Autowire bulkhead with enough terminals to run the merged pink and orange wires through the firewall so I can make the connections in the cab.

[TA_C10]

Originally Posted by MDPotter

Doors are epoxied, driveshaft is in, and I'm done reworking my LS harness. I spent hours and hours working on this harness and I'm pretty happy with it now. I initially just pulled out all the unncessary wiring and reloomed it, but then I decided I wanted to mount the PCM in the cab so I ended up shortening or lengthening pretty much every wire back to the PCM connectors. I didn't want to have the LS power wiring made up in the engine bay, so I bought an American Autowire bulkhead with enough terminals to run the merged pink and orange wires through the firewall so I can make the connections in the cab.

Nice work on all of this. Cool to see inside of doors. I did my harness same as you and made it standalone. I really wanted to rework to put in cab but for sake of time I think I'm going to leave it under hood, build a bracket for pcm, relays, and power and ground distribution, and mount all that on the core support, call that a day... Maybe in stage 2 I will redo harness and put inside cab ...

Looks great man, your re-motivating me. I'm headed out to garage with a NOS blue and I'm going to prep my cab for paint dammit

.