It was the best of times, it was the best of times. If the engineers at Buick had any inkling that the performance era was about to come to an abrupt end, there is no evidence of it whatsoever in the 1970 Gran Sports. Instead, it was all good news. Denny Manner's brilliant new 455 big block made it debut, a strong engine featuring 10.5:1 compression, big valves, and developing 350 HP for the base GS 455 and 360 HP in Stage 1 tune. Both engines developed a whopping 510 lb/ft. or Torque at a relatively low 2800 rpm- Denny liked them to be quick off the line. He was also given to understatement and admitted privately that the 360 HP Stage 1 might have really put out closer to 372, but please don't tell anyone.
And the news kept getting better. A redesigned body for 1970 with a handsome, square jawed look. A new unique split grille with a large red GS badge. Good looking dual hood scoops that were functional indeed. The 1970 GS 455 personified Buick's "Fast with Class" moniker.