Pontiac Grand Prix GTP
Pontiac made the GTP the extrovert of the L67 family: 240 supercharged horsepower, 280 lb-ft, aggressive bodywork and a chassis tuned to feel more overtly sporting than its Buick sibling.
A W2 car enthusiasts search for by name.
Factory story
Period road testing described the 1997 GTP as the performance model enthusiasts were waiting for, pairing the Eaton-supercharged Series II 3800 with a stronger four-speed automatic.
Build philosophy
The GTP’s importance today is bigger than its stock numbers. It became the center of a large 3800 performance ecosystem—pulley changes, intake/exhaust, intercooling, fuel and calibration work—while remaining usable as a street car.
Preservation note
A stock or lightly modified survivor deserves preservation; a modified car deserves documentation. Record pulley size, tune, fuel system, transmission work and cooling changes so the build can be understood later.
Build in layers, not random parts.
Baseline
Compression/health checks, fluids, cooling system, plugs/ignition, vacuum leaks, mounts, hubs, brakes and tire condition.
Chassis & reliability
Quality tires, brake service/upgrades, fresh dampers/bushings, cooling-system refresh and transmission health before extra power.
Airflow & calibration
Intake/exhaust changes and scan-data-driven calibration with fuel quality and knock control kept front and center.
More blower
Pulley/intercooler/fuel/valvetrain decisions belong together. Scan, log and tune rather than assuming a parts combination is safe.
Master Customs prioritizes factory-era documentation and period road tests, then uses established enthusiast references for service and ownership context. Equipment changed by model year and RPO; verify a specific car by VIN/RPO and factory service information before ordering parts.