Big Blue - 1980 GMC Sierra Grande K25

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When I first met my wife she was driving this GMC 3/4 ton truck.  It belonged to her family as their farm truck (in West Virginia) and when her parents passed she sold her car and started using the truck as a daily driver.  Their family had named it “Big Blue”.  Prior to her driving it the truck had sat in their barn for probably 15-20 years and had under 15k miles on it.  She had to get it towed to a local shop back then to get it running (new tires, etc).  When I met my wife she had been commuting over 60-miles a day in rush hour traffic with the truck (to/from downtown Detroit).  It ran like crap so after we had been dating a short while I made an appointment with a mechanic friend to take a look at it on a Saturday morning.  While she followed me down the highway the engine threw several rods through the block.  Apparently regular vehicular maintenance wasn't common in WV.

I had my own fleet of project vehicles to deal with so I had the truck trailered to a co-worker’s house.  She needed to get the truck running asap so I let her drive a spare car of mine while he dropped a spare 400 longblock in the truck for us that he had around.  From memory it’s a ~ ’76ish 400 block with later 350 heads, a RV cam, and had a recent rebuild.  The quadra-jet carb was shot (not sure why he didn’t swap the low mileage carb off our old motor but it was too late at that point) so another friend gave me a new Edelbrock 1406 carb with he had sitting around and a square bore to spread bore adapter.  The truck ran a 1000x better after swapping carbs (I didn’t make any carb adjustments which will need to be done soon).  More importantly I made her buy another car to keep the miles off the truck which wasn’t the most practical commuter vehicle anyway (no A/C, AM radio, etc).

Fast forward a couple years.  We got married and the wife wanted to keep the truck around forever since she had such fond memories of riding in it as a child (and we had recently sold her family farm).  The truck was now up to ~ 28k miles and starting to degrade rapidly from Michigan winters so I dropped it off with a local body guy.  I told him I wasn’t looking for a show truck but wanted to make sure the truck lasted another 30 years.  I found a clean parts truck to use for doors, bed, and other misc parts (the bed was an ’86 but not sure about the doors).  Front fenders and tailgate I had to go aftermarket since I was on a tight schedule and the originals were too far gone.  He sand blasted the frame and re-painted the truck in the original two-tone blue/silver.  The hood had a small line of rust starting on the inside front lip that he claimed he couldn’t fix perfectly (and its starting to rust again).

In hindsight I should have had him spray the frame with a more durable product than paint.  I learned this the hard way after a couple winters where rust started showing up again.  2 years ago I pulled the bed off the truck and sprayed a gallon of zero-rust everywhere I could fit the gun.  That seems to have helped a lot though there is still some rust creeping back a couple years later on the leaf springs and such.  I also should have masked everything better as I got some overspray on the freshly painted truck bed sides (oops).  Luckily its not a show truck but it still ticks me off that I was so careless.  In order to keep the bed looking good since we actually use it as a truck I had a line-x xtra color-matched bedliner sprayed in last Fall, which looks great.

Last year what I believe was the stock exhaust finally gave up the ghost.  I found a super deal on a set of lightly used tri-y headers and I fabbed up a mandrel bent 2.5” stainless dual exhaust with magnaflow mufflers (probably overkill but I had most of the tubing already sitting around the garage).  It sounds 100x better now and the engine finally can breathe.  The truck always felt sluggish and unresponsive on the highway and the exhaust change alone fixed that problem.  Throttle changes are now much more responsive and fun.

I honestly know little about working on old American cars/trucks, but I’m learning quickly.  I’ve rebuilt dozens of engines and fabricated/built various turbo setups but its all been on European or import cars.  This truck has become a fascination/obsession the last couple years and I’m looking forward to doing a bunch more work on it.  I’m told by some friends that it had the 350/th350 combo (before the wife grenaded the 350).  I’m told the full floating axle corporate 14 bolt rear is desirable.  I forget the gear ratio someone told me but its geared really low (when they sand blasted the frame the tag was lost).  I did a full brake job on it last summer and other than a strange transmission quirk where it wants to shift into 3rd gear at super low rpm (like 2500) it runs perfectly.  I’ve only shifted it into 4wd once and it appeared to work so hopefully that old cast iron transfer case won’t have any problems down the road.

I still need to clean up the overspray on the bed sides and find various clean replacement parts (NOS or lightly used are tough to find).  I’ve accumulated a small pile of parts to replace on the interior and exterior.  I picked up a '78 tach dash so I can see what rpm the engine is running at.  The tires have faint signs of rot forming on the sidewall so eventually I’ll get some replacement 16” wheels and larger tires (I suspect with the low gearing that bigger tires will help a lot with highway driving).  I found some NOS interior parts including one door panel and some trim pieces.  I am refurbing the other door panel to match.  I finally found filler necks and brackets since my ’80 parts didn’t fit with this bed.  The truck originally was a single tank but the newer bed is dual tank so I will probably “eventually” convert it to duals.  I figure if I can get my hands on some NOS fenders and hood (which I do see locally on CL occasionally) I’ll probably buy them and have them painted to match so that the truck is all original clean GM parts.  Cleaning up the engine bay is high on my priority list too.  I am probably going to pull a bunch of parts out of the engine bay and have them blasted/powder coated to get rid of some rust before it gets more serious (and clean up this filthy engine that the guy didn’t do for me when he installed it).  The oil pan has a leak so I’ll probably pull that soon and strip/paint it and look for other things to clean at the same time.

That’s the gist of our truck story.

[Boostaddict]

Here are some pictures before painting as my wife drove it every day:

[Boostaddict]

Here are some pictures after painting (a couple years ago before I started fixing it up some more):






Here are a couple pictures after I pulled the bed to paint the frame/bed:

[80stepsideguy]

Beautiful truck , welcome to the madness from florida.

thanks
Pat

[Captkaos]

Nice truck!  Cool story too.

[Got Smoke?]

Awesome story....similar to my K20 being my father's old farm truck.

Beautiful truck, hopefully I'll get started on my sometime soon. Gotta build a garage first.

[DustyRusty]

Very nice truck.  Great color combination.

BTW, welcome from Alaska.

Rusty

[big bear]

welcome man....loved the story and history .   and what a sweet truck !!!!

[bake74]

     I love to hear family history with one of our trucks, I hope she always wants to drive it and keeps the memories.

[Boostaddict]

Thanks for all the compliments. 

One story my wife always tells is how when she was ~ 5 years old she was sitting on the floor of the truck while her mom was driving into town.  Her mom was arguing with her sister or someone (also sitting in the truck) and she ran off the road and got the truck stuck in a ditch.  She said she remembers bouncing up really high in the air when she went off the road.   She thought it was so much fun she wanted her mom to do it again!

Myself, I'm wondering if her running off the road has anything to do with why the cab, bed, and bumpers all seem to sit at slightly different angles (like the frame might be slightly twisted).  Thats the car geek in me.

[beastie_3]

no, its just the classic frame twist. none are perfect anymore.

[Boostaddict]

I know its rude to bump an old topic, but since its my own intro thread and I have some more pictures, oh well

We had a little car show at work today so I cleaned up the truck and brought it in.  Its finally starting to clean up well after sitting for so long.  Need to find some new trim pieces (wheel well, body, windshield/trim) and get some newer wheels and larger tires eventually.






Engine bay looks a TON better than it did just a couple months ago (this was the before picture):