I once owned a 1965 GTO with a 4 speed. I loved that car. I had it from 18 years old to 21. I got married to a woman that had a child so it was instant family. That was 1969 and I still am married to her. She is the best thing to ever have happened to me. But I do miss that GTO. I traded it to my Dad for a 1966 Chevy Biscayne with a six and powerslide. Talk about culture shock that is it.
The switch-pitch 300 was pretty good and very reliable, but the lack of a compound 1st and 2nd made it sluggish. The non-SP versions were worse.
I’ve had a 283 ‘glide combo and a 300 Buick ST300 combo in 64/65 A-bodies. I liked the 300/ST300 much more.