What fuel should I run in my 340?

I run 92 pump gas-non oxyiginated type from BP. I have run 91 before and it pings a bit when I hammer on it, 92 doesn't do it. Sometimes I will run some 110 mixed with 92 thru it, runs great. I have fueled up at Super America gas stations before with my Valiant and my car always runs shitty on their fuel, one time it died a block away right after fueling, when I finally got it started it ran very rough for awhile, thought something was really wrong. The next day I filled it up the rest of the way with some better fuel and it ran fine. BTW, I have a 72 340 with a 9.31 compression ratio.