1969 Buick GS400 Custom Resto-Mod

This 1969 Buick GS400 Custom Resto-Mod underwent a massive ground-up restoration to become the ultimate daily driver. We combined classic Buick styling with a 575+ HP LS 427 V8 and a custom Roadster Shop chassis for unmatched modern performance.

Status: Complete

Custom 1969 Buick GS400 restomod built by Crown Customs in Tucson, Arizona, with LS376/480 power

Vintage muscle.
Modern supercar performance.

A custom-built LS 427 Super Street Series V8 pushing over 575 horsepower breathes life into this classic, mated to a T56 Super Magnum 6-speed manual. Resting on a full Roadster Shop chassis, every system has been meticulously upgraded to deliver modern reliability and track-ready handling.

Start your Build

Powertrain

LS 427 Super Street Series V8 (575+ HP, Forged Internals)
Holley EFI Engine Management System
Tremec T56 Super Magnum 6-Speed Manual Transmission
Billet Specialties Tru Trac Serpentine System
Custom Stainless Steel Exhaust with 3″ X-Pipe
Ford 9″ Rear End with Tru-Trac Posi (3.73 Ratio)

Chassis & Systems

Roadster Shop Chassis with Fox Fixed Valve Coilovers
Baer 13″ Drilled & Slotted Rotors with 4-Piston Calipers
Forgeline FL500 Gloss Black Wheels with Continental Sport Tires
Vintage Air Gen IV Magnum Climate Control
Dakota Digital VHX Gauges & InfinityBox Wiring System
Red Metallic Paint with Custom Saddle Leather Interior

Classic Buick luxury.
Relentless modern power.

The build in detail.

This 1969 Buick GS400 is the definition of a premium custom resto-mod, engineered from the ground up to be an elite daily driver. The body was completely restored, including a new roof skin, floor pans, and extensive metalwork, before being flawlessly finished in a stunning Red Metallic (Burgundy Poly Mist) paint. It rides on custom Forgeline FL500 gloss black wheels wrapped in Continental Sport tires, beautifully accented by freshly plated chrome trim.

Under the hood sits a ferocious LS 427 Super Street Series V8 engine producing over 575 horsepower. Built with a Callies forged crank, DSS Racing forged pistons, and a custom ground hydraulic roller camshaft, this powerhouse is managed by a Holley EFI system. Power is transferred to the ground through a Tremec T56 Super Magnum 6-speed manual transmission and a Ford 9-inch rear end equipped with a Tru-Trac Posi and 3.73 gears.

To handle this massive power, the GS400 was mated to a full Roadster Shop chassis featuring a parallel 4-bar rear suspension, Fox fixed valve coilovers, and power rack and pinion steering. Stopping power is provided by Baer 13-inch drilled and slotted rotors clamped by 4-piston calipers at all four corners.

Inside, the cabin was completely overhauled with custom Saddle leather upholstery, black carpeting, and a matching black headliner. A Vintage Air Gen IV Magnum system ensures optimal climate control, while Dakota Digital VHX gauges with red lighting keep the driver informed. Modern electronics, including an InfinityBox wiring system, a Compustar alarm, and a premium audio system featuring a Retro Sound Bluetooth radio and Focal speakers, complete this masterclass in muscle car modernization.