A friend of mine had a 70 GS455. No stage 1, or GSX. It was a convertible, also had just those 9.5" drum brakes that GM loved, and no H/D suspension, no rear sway bar. But It did have operational hood scoops, and it was insanely fast! Easily as fast as another friends 69 Chevelle 454, and a bit faster than another another friends 70 Mach1 Boss351 (yes it had a Boss 351). But. BUt. BUT, it was the most dangerous car! No braking from the 120+ speeds it could go so easily. No ability to turn when the road suddenly went left. Sadly, it met its fate rear-ending a Dodge Dart. (not at 120! More like 40.) Absolutely the gentleman's muscle car!