Buick's GS 455 Made It Hard to Stay Away From the Muscle-Car Mania. ... closes 49° ATC, for a duration of 322°. Valve opening overlap is 66°. Lift at the valve is .3891-inch on the intake, ...

This paved the way at Buick for the Buick Skylark Gran Sport 455 (often shortened to GS 455), which featured Buick's new 455ci big-block that put out 360 hp (4,600 rpm) and 510 lb-ft of torque ...

Larger valves with stiffer springs, high-flow port heads, a performance camshaft, ... From a salesman standpoint, the Buick GS 455 Stage 1 model had its best year in 1970.