HG's Plow Truck, '78 GMC K35 Dually
 

Last year I decided it was time to retire my old plow truck, a 76 K10. I bought it when I bought my house because we are out in the corn fields, in Minnesota, and I have a 1/4 mile long driveway. Plus a big area around the house and garages and sheds that needs to be cleared out when it snows. It was my first snow plow and for the most part it did the job. It really struggled late in the winter when the drifts and piles were big. It didn't always start easy but was okay once it fired up. The wipers worked occasionally, which is a joy when you're pushing a path on a windy day and it's blasting over the hood. It was extremely rusty. But like I said, it did the job most of the time. Until the transmission also started to fail. I used it for more than a year with only low and reverse. It had a TH350.

Anyway, I wanted something better and was shopping for a cheap early 2000s silverado. The EFI and LS motor was a plus. But the cheap ones I looked at all had frame rust or cracks or both. Then this 78 GMC K35 dually came up on FB only 25 miles away. Rebuilt motor, missing the rear dual wheels and with the wrong front axle. Someone swapped out the dually style Dana 60 for a big hub Dana 44. But it was pretty straight and the rust wasn't what I would call terrible. Not for this area.

So I went to check it out. It had been for sale for over a week and the seller was still running it from a little push mower gas tank gravity feeding the carb. ???? Okay, it started. The guy said it had been sitting a couple years and the gas in the tank was bad. I told him I wouldn't even make an offer unless I could test drive it. I asked what we had to do to get it driveable and he said we just had to get the old gas out and put new gas in. I said let's do it. We went to the gas station and filled a jug then ran the engine off the lawn mower tank while the fuel pump sucked the old gas into a bucket. It only took a minute. Put fresh gas in, hooked the pump outlet back to the carb and away I went! Grabby brakes, but they worked. 4wd worked. It didn't seem to be over heating and sounded like it was running good. Oh yeah, no gage cluster. Another bonus was that it had a plow mount but not the blade. The hydraulics had been rebuilt and most of it was powder coated and looked great. And my current plow blade would fit it, same brand and model.

We worked out a deal. $2200 which I think was fair but not exactly a steal with things like the wrong front axle, missing cluster, tires, etc. But it had potential which was something the old plow truck didn't have. Let's see if I can find the pics from when I bought it.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

I bought it and drove it the 25 miles home. The only problem along the way was when I stopped to get more gas and it was dumping fuel on the ground. The fill hose had a big hole in it so I pulled it off and put gas directly into the tank inlet. When I got home I checked the temperature of the hubs and I joints. The rear u joint was hot.

Oh and the seller had the original 16.5" wheels. The truck had 16" wheels on it and he had the full set. And he gave me a cluster but it was kinda crappy.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

There were a few things that needed to be done soon because I really didn't like the look of it with the topper and missing duals. I replaced the bad u joint and the gas filler hose. Found a better cluster in my parts pile. Found out the speedometer cable was shot and replaced that. Gave the topper to a buddy. Ordered some tires and got a pair of wheels powder coated then mounted them up. I made sure my blade fit the plow mount. And it wasn't set up for turning the blade side to side so I added the hydraulic hoses for that to work. And I replaced the cab running lights because they were toast. Luckily I didn't find a bunch of rust in the roof from leaking lights. The new LEDs were a nice upgrade.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

There was so many things to fix. And so little time. I was shut down from work with covid so I did have time but we have a short summer and winter never seems far away. The windshield was cracked and I really wanted to fix that so I ordered one and a new gasket. I never replaced one on a square before. It's different from the older style but after a few tries with the tool to get the locking strip in it went okay. But that part came after I had to fix rust in the windshield post. There's a blob of some adhesive or something in the middle of the post. It completely blocked it off so water leaking in from the busted running lights sat in there and it rusted from the inside out. I found one in the junkyard to cut out for a patch and did another rust repair for the first time.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

More pics. BTW, this is kind of a pain in the rear. I also removed the rear section of the running boards. They were corroded and I don't like them anyway.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Cool pickup. Having revived a MN pickup with a plow, I can appreciate the work involved.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Cool rehab!

Bet with some weight in the bed age is going to plow well.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

You grabbed a good one. And immediately improved it dramatically. That thing is a beast and will be worth taking good care of.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

It was a southern truck originally so it helped keep some rust away. It needs rockers, a couple small spots on the bed.
So far it didn't need extra weight. I only had to use it 3 or 4 times this winter and it pushes snow like it's barely there compared to the K10 which had to work HARD to move the deep or heavy stuff. My only gripe with the plow is this one has electric control where my old one was cable. I prefer the cable because it just seemed like you could finesse it more.
Exactly my thoughts at the time. I can fix it up while I use it and the value should follow.

The next upgrade was to the interior. I wanted it to be nice, comfortable and have everything function. I was able to get most of that accomplished but it really turned into a much bigger project than anticipated. I wanted bucket seats and a console. It needed a radio. It's an AC truck but that wasn't a priority, heat was definitely a priority. While I am mostly happy with the results there are still some things to work out but I'll get to that later.

I started with searching the junkyard for seats. I had a set of front seats from a 2003 suburban but they were for the farm truck. I found a really nice set from a 2004 F150. Black and grey cloth, I prefer cloth over leather because you don't slide around and it warms up faster. Cool looking and in good shape. But there are major hurdles using these in a regular cab square body. I'll explain as I go. I found a console to match the style which wasn't easy because most of those trucks had the shifter in the console or had a split bench with fold down arm rest console. A friend had a good grey dash pad. So I had most of the pieces to get started.

Pulled out the bench seat, dash pad, door panels, carpet, everything. And found that the water soaked passenger side had virtually rusted the floor away completely. So that needed to be addressed.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

BTW, these pics are oriented correctly on my phone so I can't tell how they will upload.

Carpet was in great shape. But I was changing colors. The floor pan change wasn't too difficult. The driver side just needed a cleaning and coat of paint. There were a couple little holes I filled. How about that rust protection?!

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Now that the rust was fixed it was time to make the seats fit. I was thinking it would be pretty easy but nope. They were too tall, narrower than expected and the seat back was THICK. They weren't power seats and I knew they would be positioned as far back as possible and always stay there. But I needed to get the seat height down significantly or they just weren't going to be usable. I almost resold them but instead I removed the adjustment tracks. That got almost 3" off. The back of the floor has an up angle so I notched it for the rear seat mounts. I tried to center the seat to the steering wheel and after I got it in I thought I had made a mistake but I remeasured and it was fine. The front mount had the seat bracket hole line up with one of the original mounts. The other side required a new bracket made to fit to the other front seat mount hole.

I couldn't find a pic of the bracket I made but it was pretty basic. Also I liked that the seat belts were incorporated in the seat. Especially since I broke bolts removing the original belts. The next challenge was the seat back, which was a little more upright than I like. My neighbor does upholstery work so I brought them to her and she cut out some of the padding at the top rear end restitched it. And also removed the headrest. That gave me a couple more degrees of recline.

In the end I don't recommend these seats in a regular cab square. Just not enough room front to back. Even after all this work the steering wheel is too close for comfort. I swapped wheels with one from a 90s truck which is slightly smaller. And I have read about some people pushing the column forward for more room. I will likely try that yet this summer.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

The console mount wasn't bad. I made a bracket for one end. The other fit the floor alright. The rest of the interior work was just cleaning and painting. I used some dye for the plastic parts. The door panels were really sun damaged on top. I used them but if this was more than a plow truck I would have replaced them. I found problems with the heater controls so they are pretty much stuck on at the heater box. The fan wouldn't go to high speed. There was crap wiring to fix. The plow control was mounted to a bracket that was where the ash tray was. The dash speaker was blown and I bought a pair of small ones to replace it. Getting that out was one of the most difficult jobs on the whole interior swap. The rear of the cab separated from the floor on the driver side. I fixed that with panel adhesive. And a big mouse nest in the cab corner.

I pretty much sprayed every piece of the interior that was used except the steel dash and the seats. The door panels I did in 2 tone and repainted the chrome trim with chrome rattle can paint. I think they turned out great. The key is getting used plastic as clean as possible so the paint doesn't get fish eyes. Every crack, scratch and pore gets body oils and other oil based cleaners like armor all in them. It sucks.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

More pics...

I went with a charcoal carpet. Also got some decent floor mats to protect it. It's all coming together here.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Carpet, seats, console, doors and dash were sorted out. Next was the stereo. Nothing fancy. I had an old 2 post clarion but the tuner adjust knobs didn't move right so it wasn't a good option. A friend had an old pioneer that still worked so I used that. The wiring was messed up of course but I got it sorted out. I found some factory cab corner speakers at the junkyard. I think I used a pair of 4" speakers in the dash and 4x10s that fit the cab corner brackets. I had to fab up a little stuff for the dash speakers but they fit and the dash pad fit over the top good.

It really needs more bass so I might add a powered sub at some point. I really don't use the radio when I'm plowing because I want to hear what is going on with the truck. But it works well when I want it.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

And the final pics...

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Wow, good refurb! And quick too. You've had this truck what, like 15 minutes? Came out nice. I don't think you said what engine it has, or I missed it.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Almost a year! It has a 400 sbc and TH400. I think it's a 208 transfer case. Rear axle is a Dana 70 with a posi. Front axle is a Dana 44. Or was. I'm just finishing up the Dana 60 swap. It had 4.56 gears but I'm changing to 4.10s.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

About the only other thing I did to spruce it up last fall was a tiny bit of body work. The dually fenders had some cracks and a hole to fix. A little bit of fiberglass and some rattle can paint. Oh and I scraped off the blue tape stripe. And this is what it looked like last week.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Winter is over and it's time to finally swap out the front axle. Last year I found a cab and chassis chassis for sale. I know that sounds odd. But I thought it was a regular dually chassis. I didn't notice the rear axle was narrower than normal. So my plan to swap both axles wasn't going to work. And the front axle needed a bunch of work that I didn't know about either. The front brakes were rusted to the rotors. The seller said that one of the stub shaft u joints was bad. He didn't know that the entire passenger side hub was full of rust.

Early winter I got the axle off the chassis and into the shed so I could work on it on warm days over winter. It took a long time to get the rotor off because after trying every method I could find I ended up cutting the hub in half so I could get to the lockout gear which also had to be cut off. Everything on the passenger side, including the stub axle had to be replaced.

Luckily I found a 4x4 shop in Glencoe that had what I needed for a decent price. Sids 4x4 for anyone interested. He was very helpful. He said he's had to cut a few off over the years.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

I collected the parts I needed and finally had some time over the last month to start putting it back together. I had the rotors turned down. The lockouts I had were pretty crappy looking. One was a Spicer, one was something else. Both had severely corroded outers. They were functional but after all the work money I put into this I splurged and got some new mile marker hubs. Stainless steel and super easy to install. I cleaned everything up and splashed some paint on it.

Another pair of new tires and powder coated wheels.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Another change I'm making is adding a leaf to the spring packs. I pulled a pair from the donor chassis. The weight of the plow only drops the front an inch but I will be widening the plow this summer. Unfortunately I wasn't able to finish the swap over the weekend. With the added height of the spring packs the u bolts were too short and I was only able to find 2 of the 3 on Sunday. I got the 3rd one made today at a suspension shop in Omaha. I'm waiting for the new shocks and steering stabilizer to get delivered. Should have it finished this week.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Interior looks awesome!

By the shifter looks like you may have an Np203.

Very cool rig

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Thanks, I think you're right. I just bought a 208 for another truck and mis-remembered what this had.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Back to work again this afternoon. All the U bolts are in and torqued. Sway bar reattached. Driveshaft on. Steering pitman arm attached. Passenger side brake hose replaced. Driver side almost. The F'ing hard line twisted right by the nut for the hose. So close to finishing. Oh well, Friday or Saturday it'll be done.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Neat 'ol truck! Glad it's worked out for ya.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

That's a stack of good stuff. That truck is set up to get the work done but will be cool to drive whenever for whatever.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

After a couple days on the road I got back on it. New brake line, both new hoses on, new shocks and steering stabilizer. Brakes bled, oil in the diff. Time for a test drive! No issues there. I checked bearing temps after. Might need to bleed the brakes again but they work fine. Just not as hard a peddle as before, which was a bit stiff anyway.

I'm still doing a couple more things to spiff it up but the axle swap is DONE!: The front is about 2" taller than before. Actually a little higher than the back now. The ride is stiff but not noticably harder than before. It looks so much better now.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Next step mechanically is to get the rear axle regeared. I bought another posi carrier and set of 4.10 gears.

For now though I don't need 4wd. Instead I did a couple cosmetic things. A friend gave me a drop hitch bumper. It was bent/twisted because some welds broke and the weight of the load twisted it. The welds were crap. Half inch plate that had a tiny little fillet welds. No penetration. When I dropped off the wheels for powder coating I asked them about the cost of doing the bumper and if they could straighten it. They wanted to give it a shot. Their welding wasn't great looking either but it was substantial anyway. It came out pretty decent. I've never seen one that wasn't chrome. This one was too before coating. But I love the look matching the wheels.

And the other thing was getting a little paint on the sides of the truck where the stripe was. I just went over it with the random orbital and rattle canned it. Just got the driver side done so far. The silver tailgate definitely needed to change. It had a little rust hole on the bottom left so I did a patch on it first. Then rattle canned it too. I'll do regular automotive paint once rust repair is done, whenever that happens. It needs rockers, maybe cab corners, some patches behind the rear wheel wells, and at least 1 cab support.

I'm really happy with how it's looking now though. Black and white is always in style.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

It's coming along nicely! Now ya gotta go find something big to hook it to and drag stuff around.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Hell yeah!!

Couple things to do first. Now the front axle is 4.10 ratio and the rear is 4.56. I have a set of gears and locker diff to get installed. When I took it out on the highway for the test drive it was lugging a bit. I've had problems with grit in the fuel clogging the jets so I put a filter on but there may still be a problem. It will need to be aligned. I put collector plates on it so to drive it anywhere I just have to contact the insurance company so it's legal.

The next upgrade I'm planning is exhaust. It has a tiny single exhaust that is choking the big 400. But that's going to wait a bit. I need to diagnose a problem with my 71 engine and get the crewcab back together. Finally done with working weekends for a while and it's warming up so that's what I'll be wrenching on.

Pic for attention...

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Since May it's mostly been parked while I work on the crewcab. That thread has been getting some updates. This last weekend I got the rear gears changed out. No real complications with that except I found out it had 4.10 gears in it. Apparently the tachometer was way off because the math worked out perfectly for 4.56 gears. Oh well, now it's got a locker. Or limited slip, whatever GM used in them in 1988, which is what the differential came out of.

First time doing a diff swap. Had a friend with some experience help me out and it's a good thing he was here because it didn't have a standard install. When I removed the inner pinion bearing race there were shims in behind it. We made a call to another guy who does these all the time and were told sometimes that was done during the set up and if the gears looked good it should be fine, just put them back in behind the new race. We did and then used the regular pinion shims according to the manual. It said to add .001 based on the numbers etched into the button on the pinion gears. We did that and it was close when we checked the gear mesh but we ended up putting the original shims back in and it looked good.

I sandblasted the diff cover because it was pretty crusty. Fresh paint, lube and got it all back together this morning. The test drive went fine. No weird noises or anything. Also I think the fuel problem I had was a weak fuel pump. It barely fills the filter up and it took forever to get it to pump after sitting a couple months. I'm thinking electric pump so it will fill the float bowl when I turn the key, then start cranking. Once there's gas in the carb it fires right up.

I also started getting things together to widen my plow. I cut 8" off each end of the donor. That will get me almost 9' wide. Still have a few months before the snow flies.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Looking good. Going to be a great plow truck

Re: HG's Plow Truck, '78 GMC K35 Dually
 

That will be a big help if you guys get a lot of snow again. If this winter is like this summer, we won't see much moisture. It's been crazy dry.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

I had an electric fuel pump from another project that still worked so I got that installed today. Seems to be working good. We'll see how it goes after it's sat for weeks. Took it down the highway way trying to get some speed out of it. Lol, not much success. It didn't start losing power like before under hard throttle. The new tires were balanced when I put them on but the rear inner inner were probably not. It shakes a bit around 60 mph.

Haven't done anything else with it. Still needs exhaust, still need to weld the plow extensions on. Still have time before the snow flies but the exhaust will probably wait. Unless the set up I pulled off the Jimmy would fit. Hmmm, just remembered that I have that in the back of the shed. Don't think I have an extra set of headers that will fit.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Betterget movin'- snow in 5, 4,3,2,....

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Come on man, it's only September.

Got the extensions welded on. It looks bigger than I expected. Still some welding to do on the face of the blade. Maybe a couple rust patches ( there's a reason I got the spare plow so cheap). Going to pressure wash it once the welding is all done and smoothed out and make it pretty with some fresh paint. Gonna look good on the beast.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

That's what... never mind.:smoke::devil:

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Those extensions will definitely help. I always cringed driving from job to job with a 9' blade, but when using it compared to a 7'5" unit, it was so much better. You're not driving in your windrows as bad in the deep stuff.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

She said. Every time. I'm beginning to get self conscious.
I rarely leave the yard with the plow on. And then it's only about 6 miles to the gas station. I'm a little concerned about the added stress on the rams, the mount, etc. Since I've done damage hitting the hard frozen stuff. And if we have another mild winter it won't bother me one bit.

Re: HG's Plow Truck, '78 GMC K35 Dually
 

Was hoping to have the plow finished this weekend but there's a few things left. The welding is done, I got it cleaned up and sprayed some paint on it. Should have bought 3 cans instead of 2. It's going to flake and chip anyway but for a minute it'll look decent. The shock absorber is shot so I ordered a new one. Almost ready for winter.

And it started much better after sitting a week or so. Really happy about that.