Dave's 1970 GMC 402 Longhorn
 

Well, I'm far enough into it now that I figured I'd start a build thread. Here's a couple of photos of the truck I'm starting with.

Re: Dave's 1970 GMC 402 Longhorn
 

Very Nice!!! I had a chence to buy one of those consoles in a salvage yard, years back...duh....

Gives me inspiration to work on mine, I have a 67 and a 68...67 will be first, I'm getting there.....

That "400" decal on RH valve cover, does it look to be factory??? Never seen one, but 396/402 pickups are pretty rare...

If you plan to keep a Q-Jet carb, later Q-Jet models are better. www.cliffshighperformance.com is the Q-Jet answer man, only way to go, my opinion.

Re: Dave's 1970 GMC 402 Longhorn
 

Yep, I believe the 400 decal is stock, and unfortunately, not reproduce by anyone.

Here's where I left off today:

Re: Dave's 1970 GMC 402 Longhorn
 

Very nice, love the color.
Posted via Mobile Device

Re: Dave's 1970 GMC 402 Longhorn
 

Well, here's where I'm at as of this morning. The first batch of parts are ready at the powder coater, so I'll be picking those up and dropping off the inner fenders and rad support!

Doesn't look like much, but man, that's a lot of parts had to come off to get here. I've got 200 photos already of stuff I was worried wasn't obvious, tons of notes, and a garage that looks like a truck exploded...

Trying to keep the work area clean, I've already been through a bag of oil absorber, and that's without draining the oil yet. Mostly fuel, coolant, transmission lines, and power steering that I wasn't able to keep off the floor as I took it all apart.

Hey Jesse, what's up with the candy-apple-red water pump? :-)

Re: Dave's 1970 GMC 402 Longhorn
 

Take some good pictures and measurements, and a sign guy could probably make you some....I'd like to see a better picture of the letters.

My 68 is a C-10, and it had chrome valve covers, no 400 or 396 letters..

Looking forward to working on mine...

Do you plan to keep it a 3/4 ton???

Re: Dave's 1970 GMC 402 Longhorn
 

Yanked the engine and transmission today. Big block plus TH400 is probably a good load for my old Harbor Freight hoist, but with the front clip off you can keep the boom less retracted.

After nicely setting it on the floor I realized I'd forgotten the flexplate-to-converter bolts (there's always something!) but after remedying that got it up on the stand nicely.

I may replace the TH400 with a built 200-4R that I have on hand, but the original motor I hope to rebuild and put back in as original.

Photo is a little blurry... stupid iPhone.

Re: Dave's 1970 GMC 402 Longhorn
 

Man, that's a great truck to start with! Do you have big plans for it, or just a freshen up?

Re: Dave's 1970 GMC 402 Longhorn
 

The plan is a complete nut-and-bolt frame-off... plans change but pretty soon it will be too far to turn back anyway!

Re: Dave's 1970 GMC 402 Longhorn
 

Haven't posted any photos in a while, but making some decent progress. Pulled the doors this week, and the interior today. Doors are complicated, but the shop manual actually had the important steps. Hope it goes back together as well, the regulators and tracks are all a little bit of voodoo.

Re: Dave's 1970 GMC 402 Longhorn
 

Nice! Glad to see its getting saved!

Re: Dave's 1970 GMC 402 Longhorn
 

Man that baby is clean!

Re: Dave's 1970 GMC 402 Longhorn
 

Excellent truck that you have there, seems to have very little if any rust. Good luck with your build and thanks for sharing with us.

Re: Dave's 1970 GMC 402 Longhorn
 

I'm tuned in :chevy:

Re: Dave's 1970 GMC 402 Longhorn
 

It's been a while, I've been working on restoring subassemblies to introduce a little variety to the teardown.

Here's the console. To polish out the metalwork I removed all the guards from a bench grinder (do not attempt, read your manual, etc) to install buffing wheels and then got grey and white rouge sticks from Home Depot. Worked well.

For the body of the console I super-cleaned it, then used a PPG "etch sponge" and then a PPG "platic prep wipe", then spayed it with plastic bond. Followed that with a coat of PPG DBC color coat and PPG DBU2060 'Fixed'n'Flat' clear.

Re: Dave's 1970 GMC 402 Longhorn
 

Wowww that looks super nice and it sound like you did it right! Do you have to buy quart containers of the ppg products or are these spray cans? I hear you on the subassemblies, its like taking smaller bites that result in more encouragement since you can see results faster

Re: Dave's 1970 GMC 402 Longhorn
 

I think pints are the smallest, but they're still $44.00. Then you need the reducer and hardener and a clearcoat. Basically about $325 to shoot your first color, I found. Plus a gun... and compressor. So it's not cheap, but the results really do seem to be better than a rattle can, and it's not like I even know what I'm doing with a gun. If you did I suppose it'd be even better!

Re: Dave's 1970 GMC 402 Longhorn
 

Dave just bumped into the thread. Couldn't have turned her over to a better a person to save her soul. Glad to see your doing all the things and details this truck deserves. Saved it from the shortbox conversion.
As for the water pump, I had a funky 454 candy apple red laying around when the water pump went out. I was in a hurry so i just put it on without painting it.
My 1971 swb project is coming along.
Looks like you are doing a great job.

Re: Dave's 1970 GMC 402 Longhorn
 

Got the cab off today. Did it all by myself, using the cab/bed lift plans from the forums and my engine hoist. Other than finding the center of gravity, it was pretty easy.

Unfortunately I have a low-rise lift that the truck is on, and it precludes sliding a hoist in sideways. I managed to use a floor jack to (not gracefully) move the truck around the shop enough to get the hoist under it, but I'm going to face the same problem when it comes time to remove the bed.

Re: Dave's 1970 GMC 402 Longhorn
 

I really like the shape of your starter truck, I haven't seen any rust anywhere

Re: Dave's 1970 GMC 402 Longhorn
 

Pressure-washing this was an -ugly- job. But hopefully I got dirty "all at once" instead of each time I work on it now... So far I've managed to do it all entirely by myself, including removing the engine and bed and body, which was tricky!

It's not immediately evident, but this is the "after" photo.

Re: Dave's 1970 GMC 402 Longhorn
 

Here's a picture of the dash cluster restoration I did. Started with a reproduction "black" bezel and masked/painted it with the body color (PPG DBC 2169) followed by PPG DCU 2060 'low gloss' clear.

Added the obligatory tach and vacuum gauges, and replaced the fuel gauge because the silkscreening was worn in places. I also upgraded it to LED lighting for the heck of it.

I found the stock gauges (like my speedo) are painted green on the back and the reproductions are bare tin, which makes the lighting brighter. I wound up putting aluminum foil tape on the back of the green-backed gauge in order to make the lighting more uniform. When you first look at the repro and see its different, you think "Who cares, no one will see the back", but it turns out to matter in the end!

Re: Dave's 1970 GMC 402 Longhorn
 

Very nice work! Your painting is looking awesome also!

Re: Dave's 1970 GMC 402 Longhorn
 

Looks good so far!

Re: Dave's 1970 GMC 402 Longhorn
 

Nice truck! Nice work!!

Re: Dave's 1970 GMC 402 Longhorn
 

Got my original factory disc brake setup from Jesse yesterday, but work is sort of at a standstill because I had to jack-hammer out the spot I'm working in so that I can re-pour the concrete to the specs needed for a Mohawk A7 2-post lift. I'm much too good looking to be crushed under a lift.

I'm starting to doubt the wisdome of rebuilding the shop while doing a frame-off restoration, but the chaos should be over in a month or two!

Here's the engine going back together...

Re: Dave's 1970 GMC 402 Longhorn
 

..

Re: Dave's 1970 GMC 402 Longhorn
 

Working on my calipers... I sandblasted and beadblasted and then painted them with Eastwood's "high temp" cast-appearing paint that's actually intended for exhaust manifolds. It's good to 1200F so should be fine for temperature, though I don't know how well it holds up to brake fluid.

Then again, if I do things right, there shouldn't BE any brake fluid on them I hope :-p

Re: Dave's 1970 GMC 402 Longhorn
 

Nice work neighbor, it doesn't seem like there are many fixing cars out here any more.

Re: Dave's 1970 GMC 402 Longhorn
 

Looks great! The truck looks like it was an awesome start for the restoration and you are doing things RIGHT!!! Nice!

Re: Dave's 1970 GMC 402 Longhorn
 

There's a few in Sammamish, but we might be the only ones working on these trucks...

Re: Dave's 1970 GMC 402 Longhorn
 

Very nice project. I really love the unique interior. The console and cluster turned out great too. Looking forward to following along on this one. BTW, that big block looks amazing!

Re: Dave's 1970 GMC 402 Longhorn
 

Nice build.

Re: Dave's 1970 GMC 402 Longhorn
 

Dave, Just found your build thread...NICE...and thanks so much for the canopy! It looks great on my Longhorn! We missed you at Monroe last weekend. Block out October 6th and 7th for a repeat out there in the fall.

Re: Dave's 1970 GMC 402 Longhorn
 

Dave good looking truck to start with.Wish I had the first shell to go on mine.

Re: Dave's 1970 GMC 402 Longhorn
 

Wow this is cool, the original owners great grandson is a board member.

http://67-72chevytrucks.com/vboard/s...d.php?t=526285

very nice project Dave!

Re: Dave's 1970 GMC 402 Longhorn
 

My shop expansion is 95% done so this week I managed to actually get the truck back in and work on it, and I got a ton done (even if it doesn't look like it, it's a lot of work to entirely strip down the chassis!)

I stuck a photo below, but it's not very informative, just a naked frame. I also stuck a photo of my control-arm nuts, which I cleaned and re-plated with tin/zinc. They're cheap to buy new, but I'm trying to re-use everything original that I can.

Below that photo is a shot of some frame repair I did. At some point in the truck's life someone blasted a jagged, golf-ball size hole through the frame with a cutting torch in order to run the trailer wiring harness. At first I just cleaned up the edges and made it look nice, but it was big enough I wondered a little about structural integrity, so I made a plug from 1/4in plate, welded it in with a MIG and ground it down.

I was pleased that I didn't have to cut anything, just used a lot of PB and pretty much everything came apart by hand, which was a treat. The bug U-bolt nuts that hold the leaf spring packs together required the impact at 175psi, but I've seen them so rusted on other vehicles that they weren't salvageable back in the midwest.

The control arm nuts took some major convincing... I had a four foot bar on it and I was jumping on it, and at 220lbs I'm sure that's close to 1000 pounds of torque, but they came off eventually. Actually my only battle was with the ball joints: I broke a pickle fork and wound up having to use a bearing separator on a couple of them.

I'm taking everything except the rear end in to the powder coater on Monday. He quoted me $750 for the entire frame and all attachments (control arms, drive shafts, springs, and so on). That includes steam-cleaning and acid-washing and media blasting of course, so it seems like a decent deal, though I have nothing to compare it to.

After the various sub-assemblies like the rear end are done I'm -really- looking forward to starting the reassembly. Nice and clean and all new parts... frankly I might have spent too many hours at it this week but I'm getting tired of being dirty!

Re: Dave's 1970 GMC 402 Longhorn
 

Painted up the motor today, started putting accessories back on. Photo below.

I wanted a rock-hard durable finish, so I wound up stripping it down (it had been hot tanked, but the valve covers and some parts were in primer), then degreasing it with Superclean and a pressure washer, then wiping it down with Superclean, then with PPG wax and grease remover.

I shot the primer coat with PPG DP40LF, which is a catalyzed primer that contains zinc that supposedly chemically bonds to the underlying metal.

I followed that with PPG Delstar acrylic enamel. It's getting hard to find these days (not commonly used, and it contains lead). At over $100 a pint it's precious stuff, but everything I've read indicates its the most durable choice for engines and retains its gloss well.

Turned out quite nice. I did run into a problem with the exhaust manifolds, which do not clear the head studs (seems I pay a price for every deviation from stock design), but I've corrected that.