College room mate was the son of a Buick dealer. He had two 1970 GS's. A GS 455 and a Stage 1 GSx. Those were pretty much garage queens, but he did drive the GS 455 on the street and it would lift the front end when he had the street slicks on.
His daily driver varied, but for most of one semester, he had a Grand National. That thing was stupid fast. Total sleeper. I remember blowing a convertible Jaguar off the road one weekend in Dallas. The SMU frat boys were in awe when they caught us at the next redlight.
I would rank that car up with the funnest cars I ever got to drive.