For many enthusiasts, building a classic truck begins with months - sometimes years - of searching for the perfect project. For Denny Ruan, it began with a single phone call. Today, nearly three years after that moment, his 1987 GMC Sierra R10 stands as a lowered, tastefully modified cruiser that blends late-’80s squarebody style with personal touches and family craftsmanship.
The Call That Changed Everything
In the fall of 2022, Denny wasn’t thinking about buying a truck. His attention - and his savings - were focused on restoring his 1979 Pontiac Firebird. Then came the call.
On the other end of the line was his uncle, with an intriguing offer: “I’ve got a truck I think you’d like.”
Curiosity got the better of him. Denny drove over to take a look, and there it was - a clean, well-kept 1987 GMC Sierra R10. The last of the “squarebody” generation, the R10 marked GMC’s transition from carburetors to fuel injection, bringing a blend of vintage styling and more modern drivability. At $12,500, the deal was too good to walk away from. That day, the Firebird project went on hold, and the Sierra came home.
Family Hands-On Build
From the start, this wasn’t just Denny’s project - it was a collaboration between him and his uncle. Together, they tackled nearly every modification on the truck themselves, turning wrenches in the garage and sourcing the right parts for the look and performance they wanted.
“I’ve always liked doing my own work,” Denny says. “There’s just something special about knowing every bolt and bracket was put on by your own hands - or in this case, by me and my uncle.”
The only thing they left untouched? The engine and transmission. This Sierra still runs the original 350 cubic inch small block V8 with throttle-body fuel injection paired with the stock 700R4 four-speed automatic transmission - both of which remain untouched and still running strong.
The Stance: Low and Mean
One glance tells you this Sierra isn’t sitting at factory ride height. The truck has been lowered six inches up front and seven inches out back using components from DJM Suspension in Gardena, California. This gives the GMC an assertive, level stance that perfectly frames its squarebody lines without sacrificing too much drivability.
Future plans call for an even more radical wheel and suspension setup - 24x15-inch rears and 22-inch fronts mounted on coilovers from Grant Fab, with Pro Wheels tying it all together. The goal is a truck that rides as good as it looks, while planting those massive rear tires deep into the fender arches.
Lighting the Way Forward
Classic trucks look great in stock form, but modern lighting can make a world of difference - both in appearance and safety. Denny swapped out all the factory lamps for LED upgrades:
- Front lighting from Octane Lighting for crisp, bright illumination.
- Rear taillights from Holley Brothers for a clean, updated look.
- A third brake/cargo light from United Pacific for better visibility and a contemporary touch.
These upgrades maintain the truck’s original styling cues while providing a much-needed boost in brightness and reliability.
Fuel System Upgrade
One of the more functional modifications was relocating the gas tank. Using a Holley Brothers relocation kit, Denny moved the tank from the factory side-mounted position to the rear of the truck. This change not only improves weight balance but also cleans up the truck’s profile and eliminates the “side saddle” look, a common step among squarebody enthusiasts.
Squarebody Power: Stock and Strong
Unlike many builds where the powertrain is swapped, rebuilt, or heavily modified, Denny’s Sierra keeps its original mill - a 350 small block Chevy V8 with factory throttle-body fuel injection. It’s a setup prized among late-’80s GM truck fans for its reliability, simplicity, and torque-friendly nature.
Mated to the durable 700R4 overdrive transmission, the truck delivers smooth cruising on the highway while still having the gearing to pull hard when needed. For Denny, keeping the original drivetrain was part of preserving the truck’s authenticity. “It runs great, and it’s never given me a reason to crack it open,” he says.
From Weekend Cruiser to Showpiece
Since its completion, the Sierra has mainly been a cruise and show truck. It’s a machine built to be seen - rolling into meets with a low stance, gleaming paint, and that unmistakable squarebody silhouette. And while it’s no stranger to drawing a crowd, it’s also a truck Denny enjoys driving.
“I didn’t build it to sit in the garage,” he says. “It’s meant to be out on the road, turning heads and having fun.”
The Classic Industries Connection
No custom build is possible without access to the right parts, and for Denny, one supplier stood out during the process. “Classic Industries has been great. They had every part I looked for. And customer service has been great,” he says. Whether it was trim, lighting, or other restoration components, having a reliable source for factory-correct and performance parts made the project smoother and more enjoyable.
The Road Ahead
As October approaches, Denny will mark three years of ownership. But in his mind, the Sierra’s story is far from over. The planned wheel and suspension upgrades will push it further into show-truck territory, and he’s always looking for new ways to refine and personalize it.
For vintage GMC truck enthusiasts, Denny’s Sierra is a reminder of why these squarebodies have such a devoted following. They offer timeless styling, rugged construction, and endless potential for customization - whether you’re restoring one to factory spec or building a head-turning custom like his.
Specifications & Highlights
- Year/Make/Model: 1987 GMC Sierra R10
- Owner: Denny Ruan (since October 28, 2022)
- Purchase Price: $12,500
- Engine: Original 350 cubic inch small block V8 (TBI, never rebuilt)
- Transmission: Original 700R4 automatic (never rebuilt)
- Suspension: DJM Suspension (6" front, 7" rear drop)
- Fuel Tank: Holley Brothers rear relocation kit
- Lighting: Octane Lighting (front), Holley Brothers (rear), United Pacific (third brake/cargo)
- Current Use: Cruiser and show truck
- Future Plans: Grant Fab coilovers, Pro Wheels (24x15 rear, 22 front)
A Build Born from Opportunity
Above: Denny's GMC has starred in some music videos. Several of the celebrities involved have offered their signatures.
What began as a detour from a Pontiac restoration has turned into a lasting passion project. For Denny, this 1987 GMC Sierra R10 isn’t just a classic truck - it’s a reflection of family effort, smart choices, and the joy of preserving and enhancing a piece of automotive history.
And for those who share his love of vintage GMCs, it’s proof that sometimes the best builds aren’t the ones you plan - they’re the ones that find you.
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