Buick GNX
Grand National Experimental: Buick’s ASC/McLaren-developed final statement for the rear-drive turbo Regal era.
More than a Grand National with badges.
GNX conversion work added revised turbo/intercooling hardware, exhaust and calibration changes, unique instrumentation, 16-inch wheels, fender vents/flares and significant rear-suspension changes designed to improve launch behavior and axle control.
Powertrain
Still rooted in the Buick 3.8L turbo V6, but with GNX-specific hardware and calibration. The official 276-hp/360-lb-ft rating is the historical factory number Master Customs uses.
Chassis
The rear suspension is one of the defining technical differences. A torque-arm/Panhard-style arrangement was used to control axle motion differently from the regular Regal layout.
Identity
Numbered production, GNX-specific trim, wheels, vents, flares and instrumentation make provenance essential. A convincing clone can duplicate appearance more easily than history.
Documentation is part of the car.
Verify provenance
Use GNX number, VIN, original documents and registry/history evidence. Do not rely on exterior parts alone.
Inspect the conversion hardware
GNX-specific suspension, instrumentation, turbo/intercooler pieces, wheels and body details should be evaluated together rather than as isolated cosmetic cues.
Master Customs treats period factory literature as the baseline and separates factory configuration from enthusiast modification. Turbo-Regal terminology changed by model year, so a specific car should be verified by VIN, RPO/SPID information, original documentation and drivetrain codes rather than appearance alone.