Those old Buicks were just damn fast! I see them at the Woodward Cruise every year. They always light up at the stoplights. Not burn outs, just leave the light quickly, very quickly. It was a great GM car that they've not really repeated.
As for the GTO, my dad hadf a '65 with the 389 4-bbl, convertable. The 4-speed was nice. I was just learning to drive and it was a great car to learn in. Dad was a bit miffed when he had to replace the clutch at 30,000 miles. He told me he couldn't figure out why it didn't last longer. I just nodded in agreement with a small smirk.