GM's corporate restriction on engines larger than 430 cubic inches had been lifted. This paved the way at Buick for the Buick Skylark Gran Sport 455 (often shortened to GS 455), which featured ...

Buick didn’t roll out impressive production volumes for its hard-hitting GS 455, though – the price was a big deterrent, and whoever wanted to flex at the local strip or in between stoplights ...

Produced for just three years (from 1970 to 1972), the Buick GSX started its life as a performance package atop the Gran Sport ... 70 GSX with Stage-1-equipped 455 V8s churning out 510 lb-ft ...