1967 GMC - SWB, great patina
 

After nearly a decade of watching this C10 sink lower and lower into the dirt, I recently picked up this ‘67 and will be puttering over the winter.

It was in Texas around 1982, went to Colorado at some point and wears a 1999 license plate. It came with a spare rear glass wrapped in Colorado newspaper from 2009, then I first laid eyes on it in Vermont in 2015.

250 / 3 on the tree, replaced with an SM465 & high hump. Tags on the Dana44 indicate 3.54’s with limited slip ✅

——

I jacked it out of the grass, pulled all 4 wheels, shoved in tubes and aired it up enough to drag across the lot and onto the car hauler.

It ran on starting fluid after buying an HEI, but wouldn’t pump gas and what I did cram in, poured out of the carb like a watering can.

Very solid bones, especially for sitting in the grass for a decade. A couple cab mounts are tender but all there, the rockers and cab corners are structural but have some small holes starting. Floors are mint, as are the firewall, cowl vent leaf collection area, drip rail, etc etc.

A local locksmith cut me a few keys with the code from the door cylinder, which luckily matched the ignition.

First photo is when i saw it in 2016. From there, photos are current

Re: 1967 GMC - SWB, great patina
 

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Re: 1967 GMC - SWB, great patina
 

My '72 also had the Texas sunburn when I bought it in 2007

https://67-72chevytrucks.com/vboard/...ictureid=27077

Re: 1967 GMC - SWB, great patina
 

Watching this one! ;)

Re: 1967 GMC - SWB, great patina
 

What a beauty, congratulations!

Re: 1967 GMC - SWB, great patina
 

WCT,
I like it!!!
Are you going to maybe do the CLR treatment on the rust? That rust looks serious...

Looking forward to what you do!!!

Re: 1967 GMC - SWB, great patina
 

Thanks all - the rust isn’t “deep”. It’s what’s happened with NO paint left on the hood or roof, or fender tops, or bedsides 😆

Educate me on what CLR will do for it? Plan right now is to take it apart (underway) and get things to a point where I can move large pieces over the winter.

Re: 1967 GMC - SWB, great patina
 

Taking things apart so they can be mobile and stored away for the winter.

When I did my ‘68, it was scattered from hell to breakfast across my garage and everything was always in the wrong spot, no matter where it was.

I have rolling carts for the bed, front clip, cab, and a rolling table for the frame. More bueno.

I have away the 250 / SM465 to a local fella for a K10 project and have acquired a GenIII 6.0 with T56 from an LT1 car - going through the mid-shift conversion, and conversion to LS style.

I know everyone does an LS swap and it’s pretty overplayed….but after doing it, and driving my truck 6500 trouble-free miles this summer, having it start and run perfectly every time, getting 20+ mpg, and having a huge aftermarket / knowledge base to draw from…..it’s really a no-brainer.

Re: 1967 GMC - SWB, great patina
 

Discovered the Dana44 has 3.54’s and a limited slip (at least based on the bolt tags which are still there and legible) - a fair starting point for a T56 cruiser.

Re: 1967 GMC - SWB, great patina
 

After thinking it over for a couple weeks and parts-shopping….im going to stick with leafs in the rear, do a flip kit and keep the Dana 44 if it all looks good inside.

I considered going to trailing arms with coils or bags and converting to a 12-bolt with panhard bar provision, considered coil overs, but for a nice driver and being budget-minded, I’ll stick with the Dana and leafs.

My ‘68 had $1,300 into the rear end, adding a TrueTrac, new ring & pinion, all new bearings etc. Since this is already limited slip, already a reasonable gear ratio for a T56, and already has bracketry for leafs, I’ll stick with what I have and put the money elsewhere, aside from a new set of 5-lug axles and rear disc conversion stuff - very pleased with the setup on the ‘68 from Captainfab with ElDorado calipers (cable actuated e-brake) and K1500 rotors.

Still up in the air on front suspension. Lower control arms are pretty rusted and pitted, and bushings are toast, so refurb doesn’t seem like the best idea. I love the simplicity of coils, but my ‘68 sits about 1” low on the drivers side and there’s no real way to change that nicely. Coilovers would allow adjustability but that’s knocking on $2K once done with control arms and coilovers. I like the stance of the ‘68 with CPP drop spindles, and 3” springs in the front, and 5” springs with a 2” block in the rear. Aiming for the same stance with this truck but will go with a larger wheel. The 15” steels BARELY, clear the rear calipers, and hit on the CPP spindle where the tie rod attaches on the front at anything more than 3/4 of full tight-turn. I’ve cleaned off wheel weights all summer 😒

Planning to stick with the stock front crossmember but will change oil pans. The stocker hangs pretty low on my ‘68, so investigating options to change them both out.

Re: 1967 GMC - SWB, great patina
 

Removed the leaf springs and disassembled the diff a bit to see what I was working with. The stamps on the ring gear match the tags. The limited slip seems locked up though. I could not get the wheels to spin independently at all.

I pulled the cover, drained things, washed with brake clean and inspected. For the life of me I cannot get the spider gears to turn (at least reaching in and trying to rotate the gear by prying on the teeth gently with a screwdriver).

I pulled the axles, the drivers side seems “normal” but the splines on the passengers side seemed to have some debris / crud in the splines? It was just black gunk so hard telling but it’s been sitting a LONG time without moving.

I’ll pick up a differential spreader, pull the carrier and inspect further, unless anyone has a recommendation while it’s all still in place?

The frame works pretty well as a makeshift workbench.

Re: 1967 GMC - SWB, great patina
 

For the T56 mid-shift conversion, I opted to close up all the offices of the tranny with tape etc and cut the shafts in place, versus a full disassembly. As others have shown, the cut off wheel does get into the side of the case a smidge but nothing that will cause any issues or leaks.

Also opted to drill a 9/16” hole in the rear of the tail housing to remove / install the rear shaft, versus taking the rear housing off.

Drilled & tapped for a 3/8 NPT plug.

I replaced the skip shift solenoid with a plug, and will disassemble & cut down the spring on the reverse lockout solenoid versus buying a $60 spring-loaded replacement spring-loaded plug. I’ve done this before and it worked perfectly. Cut down the spring to the point where you can push past it and into reverse, but it provides enough resistance so you don’t accidentally go 4th to Reverse.

Re: 1967 GMC - SWB, great patina
 

T56 back end is tidied up and sealed. I will send the mid plate out for machining and a slave mounting plate to convert it from LT to LS, them add a new input shaft & bellhousing. That will put a bow on the job. The SilverSportTransmission (SST) kit is pretty nice but on the mid-shift metal piece the shifter now slides into, one roll pin hole was 3/16” and the other was machined at maybe 1/8”?

The options were to leave the adapter and drill - pin the shaft with 1/8”, or machine the hardened adapter and hardened shaft to 3/16”. I have access to a Bridgeport mill, so opted for the 3/16” extra-machining path.

Bought a carrier spreader tool to help me pull the carrier out and prep for LSD clutch replacement. The tool worked great, diff came out smooth and looks nice. Good wear pattern on the gears, no chips.

Re: 1967 GMC - SWB, great patina
 

There are 8 leaf springs in the back of this 1/2 ton, but all are in good shape.

Can I remove a few, and if so….which do I take / not take, and how many should I leave for a rig that’s a pavement daily driver that might occasionally haul 500-1000lb?

Re: 1967 GMC - SWB, great patina
 

Subscribed!

Re: 1967 GMC - SWB, great patina
 

Spent some time cleaning up the rear end with a wire wheel on an angle grinder, and took the needle scaler to the engine a bit to get rid of flaky stuff in prep for paint. Placed an order with Jegs for some replacement clutches & washers for the diff, and various gaskets.

I’ll be converting to 5x5 axles so will need to source those……and new seals / bearings while I’m at it.

Test fitted the LS1 intake after removing all the accessories, and carved time to get the plow truck set for the winter 😎.

Re: 1967 GMC - SWB, great patina
 

I’ve made mention to my ‘68 a bunch, and am overall very pleased with it - there are a lot of things I’ll take from that build and incorporate here. Plenty of things I’ll do differently as well

Some ‘68 details
Bought as a garage bay / storage unit of parts that the owner had torn down and accumulated restomod parts for. Nice low mileage GenIII 5.3, drive by wire stuff, POL tubular upper control arms, CPP drop spindles, a plastic bin of tie rods, ball joints, sensors, etc etc etc. A real project.

It’s a ‘68 short bed fleet side from Michigan that was in South Carolina in the 90’s+. 100% original sheet metal, original frame with VIN stamps, original 12-bolt. Someone hacked doing floors, rockers and cab corners during the rebuild, so the doors wouldn’t close, etc. A bit of a mess but super solid bones and an awful paint job somewhere along the lines.

Originally green, it’s now white / black but has red under the white / over the green, but only on the doors? I LOVE the paint, it’s cracked and falling off. Every day it’s driven, another chip comes off.

5.3, 4L60E, 12 bolt Eaton TrueTrac 3.73’s, front & rear disc (Rear ElDorado setup from CaptainFab), American Autowire chassis harness, handmade LS harness tucked nicely through a firewall grommet to the ECU behind the dash with bone stock 5.3 tune from GM. No HVAC at all, manual steering, mechanical fan, only the minimum under the hood, battery under the bed, ‘69 f-body fuel tank under the bed, Classic Instruments gauges.

New inner fenders and radiator support. A lot of this truck inspires what I want to do on the ‘67 but also shows me things I want to change.

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Re: 1967 GMC - SWB, great patina
 

What I love and will do again
- LS engine, and drive by wire, GenIII. Just all around great
- Eastwood products for framework (Rust Encapsulator Platinum
& Extreme Chassis Black, both sprayed on.
- 4wheel power disc brakes
- exhaust with cats & “quiet” mufflers. Drone sucks - I love how this truck sounds.
- Classis Instruments dash looks stock.
- American Autowire kit was awesome.
- will buy new inner fenders & radiator support again vs finding good used stuff
- love the bench seat



What I’ll do differently.
- 6spd manual. Auto is a GREAT driver but a T56 is so so great.
- larger rimmies. The 15” steels BARELY clear the rear calipers with a 1/4” wheel spacer to get more gap, and they hit on the front spindle where the tie rod attaches. At full turn I clear off wheel weights. Sucks.
- power steering. Manual is simple & fun except under 5mph
- will do heat and AC
- will do a rear tank that feeds through the taillight or directional. The ‘68 is behind the license plate which is cool but the tank hangs low and it’s sort of a pain.
- will put the ECU, battery etc nicely buried under the hood somewhere.
- will do carpet instead of vinyl floor.
- pretty disappointed with the sheet metal door latches (name escapes me but similar to Trique). The hardware loosens up on me, the striker pin rattles over bumps. Unfortunately you cut the door to fit them….and I’d give it a C- on happiness. Wish I’d used good original latches.
- build my own harness. I learned SOOO much building the harness wire by wire from each sensor, back to the ECU. Refined wondering & heat shrink skills, researched pinouts, learned what was and wasn’t necessary. I wouldn’t trust a turn-key aftermarket harness made by someone else.
- will go electric fan and get rid of the mechanical. I did it for simplicity but the depth of the fan in the shroud is what drove the position of the entire drivetrain. Too far forward and the fan was buried in the shroud. Too far back and it wasn’t going to pull air through. Will just go electric this time.

Re: 1967 GMC - SWB, great patina
 

I love the plan. LS with 6-spd manual and quiet exhaust will be sick.

What are you thinking for interior? Redo in new blue vinyl?

Re: 1967 GMC - SWB, great patina
 

Unsure to be honest but the thought is lurking. When the conversion from the original 3spd to the SM465 happened….the original low-hump floor was pretty hacked up and covered by the bolt-on high hump to accommodate the HUGE 4spd.

I believe the T56 will fit nicely under a low-hump floor, which I would prefer. There’s a local junkyard that somehow has a few of these trucks left, so I hope to make a bolt-on low hump to restore the original floor….then cover with carpet. The ‘68 has a non-folding bench from a ‘70 (from the same junkyard where I needed to literally cut down a tree, to open the door to extract the seat last Dec) that is “period correct”?? Its tweed / something else, and had been sitting in this truck since being parked in the junkyard in 1998…..



……THIS is the interior I’m after. Not just throw an Indian blanket seat cover on and claim “it’s old, it’s cool”……something a notch older and cooler, like NAPA Balkamp C10 seat cover that was new for NAPA in 1991 but has been sitting on the shelf in shame since.

Re: 1967 GMC - SWB, great patina
 

Despite the cold and snow, I ran the wire wheel a bit in the driveway with some wind, to help dissipate the rust dust. The axle is cleaned up and largely ready for primer. The cover isn’t really salvageable, so I’ll buy a new one.

I uncovered some stamping on the axle tube, “ 4 10 7 B “ if anyone has any ideas?

April 10 1967, 2nd shift?
4th day of 10th week of 1967?

The tube where the leaf spring brackets mount are pretty eroded, but should be fine.

Re: 1967 GMC - SWB, great patina
 

Nice work so far. It’s cool you saved that one.
There’s a thread on here somewhere with an axle decoder.

Re: 1967 GMC - SWB, great patina
 

Thank you -
I searched a bit and only found BOM (bill of material) stiff - nothing for the stamping, but I’ll keep looking.

Ordered a bunch of parts from Jegs, but tis the season for late deliveries, so still just cleaning.

Propped up the trans to fully drain before I pull the front midplate off for modification and a new LS input shaft, cleaned up the engine a bit and have to extract 1 broken exhaust manifold bolt (easyPeasy), and cleaned up the diff cover.

They are $40 and I thought “if someone paid you $40 to get this workable again, would you?”….plus I’m sure it’s better quality than anything from China made today.

Re: 1967 GMC - SWB, great patina
 

Removal of the heater box, and cleaning of the coil & vent area. Amazing how much stuff accumulates in there. After pulling both vent doors out, it was a lot of vacuuming, and compressed air from the vent, the “drain” and cowl to get things empty. Pictured - the dirt that came out which wasn’t vacuumed.

Great news is no holes or concerning rust discovered anywhere ✅

Also took some time to remove the fuel tank, and vacuum the floors to get a better look at things. Not perfect by any means, but certainly very very workable, even for someone like me.

Re: 1967 GMC - SWB, great patina
 

I spent 90mins with a grinder & wire wheel on the frame, getting a first pass on the exterior. It’s not as clean as my ‘68 (which was beautifully coated in a TON of old oil, grease, grime etc which perfectly protected the frame), but this was a nice surprise. No pitting, no significant scale. Just dry surface rust that came off in a big red cloud.

Some frame stampings were exposed, and I realized the leaf spring frame has bulged ribs by each leaf spring shackle, where my coil spring ‘68 frame was just straight flat frame rail. I assume for strength.

Parts continue to slowly roll in….

Re: 1967 GMC - SWB, great patina
 

After a week and 6 unreturned asks to buy a used engine lift on Marketplace, I slunk to Harbor Freight and bought their $99 cheapie - will hold the 6.0. I searched Craigslist but that place has officially died. Searching “engine stand” get you used cars, mixers, hiking boots, anything but an engine stand.


The dipstick had broken / rusted off flush with the block, and I picked up a 302-1 oil pan kit. The truck pan hangs below the crossmember in my ‘68 so I wanted to change that this time around. From the underside the cylinder walls still have some crosshatch showing, and nothing looks awful. Used a brass punch to pound the dipstick back up/out. The Dorman 917-303 tube I bought would NOT fit. It measured 0.010” larger diameter than the original tube. I’d already dinged it up attempting to install, so used a flap wheel on a die grinder to turn the OD down a sniff. Covered it in never-sieze and sent it home.

Waiting on a timing cover alignment kit to arrive from the Bezos to continue work…

Re: 1967 GMC - SWB, great patina
 

Removed as much rust and scale from the LQ4 as possible with an a needle scaler then various wire wheels before hitting the block with POR15 engine enamel.

Took apart the rear axles to get measurements for an order to Dutchman. I had to cut off the retainer, and bearing for measurements but the new axles will come with bearings & retainers installed.

Specs
- 29-5/16” & 31-5/16” length
- 30 spline
- 5x5 bolt pattern
- Pilot hub turned to 3-1/16” to fit most standard rotors EX: Wilwood
- Outer flange turned to 6-1/8” OD for fitment in most - GM applicable rotors if I go that route
- 1/2-20 screw in studs 3” long. Press-in were only available in 1-3/4 and 2” long….and I want more length, not knowing what wheels, spacers etc might be needed later in the game.

Re: 1967 GMC - SWB, great patina
 

The Dutchman model of axles for an early GMC Dana 44.

By changing the pilot and outer diameter, I deviated from a “stock replacement” with only a pattern change and was moved to “full custom order”.

$499 shipped for the pair.

Re: 1967 GMC - SWB, great patina
 

Documenting for anyone in the future needing the info.

I used a large pipe wrench on the yoke and breaker bar on the pinion nut after making a reference mark with a die grinder for reassembly. With no crush sleeve, I’ll tighten the nut to where the marks line up again.

Ordered some rebuild parts today for the Dana 44

Pinion seal
DANA 44895

Axle Seal
CENTRIC 41766015

Re: 1967 GMC - SWB, great patina
 

52* today so hauled the crossmember to the driveway for some cleanup. I’d love to go with a different crossmember, or even to rack & pinion….but maybe another day. Things cleaned up nicely with just a wire wheel on an angle grinder.

I’ll leave it bare and covered in the garage until spring when I can spray the whole chassis in Eastwood stuff. Gives me time to drill & tap for brake line retainers, fuel line clips, electrical stuff etc before paint is laid down.

Re: 1967 GMC - SWB, great patina
 

Job well done!!!

Re: 1967 GMC - SWB, great patina
 

Nice work. Facebook Marketplace drives me crazy...

Re: 1967 GMC - SWB, great patina
 

Thank you. Unfortunately it’s infinitely better than CL….so you get what you get I suppose ��

Diff parts are due shortly - looking down the axle tubes, the upper section of the tube (not where oil was sitting) has some rust, scale, debris etc.

I didn’t want any of these bits to fall / wash off in oil once on the road, so I rigged up a wire wheel on a couple drill bit extenders, dunked it in bucket of carb cleaner and honed the insides to get rid of as much as possible. It turned out ok after hosing things down with brake cleaner and running nice clean rags through a handful of times.

First 2 before, second two after.

Re: 1967 GMC - SWB, great patina
 

Also spent a sniff of time on the engine. Installed the 302-1 pan, the freshly stripped & painted timing cover, valve covers, valley cover and coil brackets.

Re: 1967 GMC - SWB, great patina
 

My ‘68 with a 5.3 has the rear steam tube locations plugged, and the standard truck front steam pipe. That pipe is tied into a nipple I threaded into the water pump. I wanted a 4-corner steam pipe for this 6.0, and looked at all options….finally settling on a standard issue LS1 pipe. I’ll do the same thing when I decide which water pump / accessory spacing I’ll go with - drill & tap for a barb to aid in air bubble venting.

Also picked up an inch-pound torque wrench for setting pinion bearing preload on the 12-bolt in the ‘68.

Any excuse to buy a tool….

Re: 1967 GMC - SWB, great patina
 

Finally received some goods, so got after the rear diff reassembly with a new pinion seal, pinion nut and axle seals. On just about everything I assemble, it gets a LIGHT tough of Loctite 518, including a small line around the splines of the pinion and yoke.

I cleaned the heck out of the original bearings and coated them in 90w before reinstalling, tightening the pinion nut to a rotational torque of 15inchLb for the pinion. Used a big pipe wrench to hold the yoke.

Re: 1967 GMC - SWB, great patina
 

New toys!

Re: 1967 GMC - SWB, great patina
 

Were the original drums from the six lug axles any good yet or were yours bad?

Re: 1967 GMC - SWB, great patina
 

They were probably usable….but I had no intention to stay 6-lug let alone drum, so they went to scrap metal.