For fans of squarebody pickups, this 1986 Chevrolet C-10 listed here on eBay strikes an interesting balance: period-correct looks paired with a thoroughly modernized drivetrain. The seller describes the truck as having a clean body and interior, largely original in presentation, though it appears to have been repainted once. At 122,487 miles, it’s been well-preserved, with only small spots of rust and wear showing through.

Under the hood, however, things are anything but stock. The factory small-block has been replaced with a 5.3-liter V8 sourced from a 1999 donor with about 120,000 miles. The swap wasn’t just about dropping in a newer engine—this C-10 benefits from a full suite of supporting upgrades. A Norris BTR camshaft, pushrods, and upgraded lifter springs set the tone, while a Holley intake and Sniper EFI system (with matching wiring harness) handle fueling and tuning. It’s all backed by Doug’s headers, MSD ignition, and a carefully routed 3-inch stainless dual exhaust with an “X” pipe. Cooling is handled by an Entropy aluminum radiator paired with dual 12-inch electric fans.

The supporting hardware shows the builder’s attention to detail. The fuel system is entirely new, from the Holley tank and pump to the fresh lines and inline pressure gauge. Electrical needs are covered by a Powermaster alternator, new battery, and all new cables. Even smaller items—like a new washer reservoir and water temp sensors—were addressed. Inside the cab, the original bench seat has been reupholstered, new felt and carpet installed, and fresh window seals fitted, leaving the interior looking crisp and close to factory spec.

The chassis and driveline haven’t been ignored. A Yukon 3.73 limited-slip 10-bolt rear end was fitted, along with a new carrier bearing. Suspension was refreshed with replacement shocks at all four corners, while braking was improved with new components front and rear. Tires are also fresh, mounted on powder-coated original steel wheels that preserve the truck’s period aesthetic.

Visually, this C-10 stays true to its roots. Finished in blue with a matching blue interior, it retains the understated appearance that made these pickups so popular. It’s only when you pop the hood or step on the throttle that the upgrades become obvious.

For someone seeking a squarebody that can be driven and enjoyed today without the compromises of 1980s technology, this build makes a compelling case. The blend of original presentation and modern powertrain should appeal both to restorers who value authenticity and to enthusiasts who want reliable performance in a classic shell.

Would you keep this C-10 looking stock as a sleeper, or highlight the modern hardware with a few exterior tweaks?