1966 Buick Riviera GS Matching Numbers, Custom Build, Amazing Car!

1966 Buick Riviera GS This stunning 1966 Buick Riviera GS is a masterful blend of originality, craftsmanship, and tasteful modernization. Powered by its numbers-matching 425ci/340HP Nailhead V8 paired with the original ST400 switch-pitch automatic transmission, this Riviera delivers the smooth yet commanding performance that defined Buick’s Grand Sport heritage. The car has been extensively upgraded mechanically, featuring a completely rebuilt suspension, 4-wheel Wilwood disc brakes, a custom Strange 3.55 rear differential, and fast-ratio power steering. Performance enhancements include an MSD electronic distributor, QFT Slayer 750 carburetor, custom headers, and a polished 250-amp alternator—ensuring modern reliability and spirited drivability.