As one of the biggest and “baddest” cars created by Buick, the GS Stage 1 was powered by a new 455cui engine in 1970, following the lift of GM’s corporate ban on engines larger than 400 cubic-inches. Rated at 360hp but believed to produce upwards of 400hp, the big block pushed out a whopping 510 pound-feet of torque. To top it all off, if ordered with the GSX appearance package, the potent muscle car came equipped with front and rear spoilers, beefier tires, contrasting body stripes, heavy-duty suspension components and a hood-mounted tachometer.

The GSX up on eBay underwent a complete frame-off restoration from Then and Now Automotive in Woodstock, Georgia. Finished in Arctic White, one of the two factory colors for the GSX, the car was restored to factory correct conditions all the way down to the nuts and bolts.

But this isn’t just a car restored to factory standards, it also maintains many original, numbers-matching parts. The GSX remains equipped with its original 455cui Stage 1 engine, which includes a hotter camshaft, revised jets in the Rochester Quadra-Jet carburetor and bigger valves than the 400cui engine previously put in the GS models.

The GSX also comes with its numbers-matching close-ratio 4-speed transmission, a transmission that came in only 188 of the 678 GSXs that were manufactured in 1970, as well as its numbers-matching Posi-traction rear end.

As a premium muscle car, the GSX sports firmer front and rear shocks, a rear stabilizer bar, rear lower control arm assemblies and rear firm ride springs with the factory Rally Ride Control Package. The GSX also has factory power-assisted brakes with new lines, a new fuel tank and lines, new body mounts and a fresh coat of GM undercoating. The interior of the GSX features updated black vinyl seats and door panels that set off the wood grain and chrome details.

This pristine GSX is being offered on eBay for $159,900. While this price may be a bit steep for an ordinary muscle car enthusiast, it may be well worth it for a collector to own this historic and rare Buick. Documentation from the Buick GSX Historic Society and Concours Gold plaques from the Buick Performance Group Nationals and GS Nationals come with the sale of the car.