race gas or pump non ethanol premium, which to use

Rapid Robert said
360 2bbl 9-1 CR stock car. either one is allowed. assuming pinging ain't a potential would one work better than the other? burn time & all of that which I know nothing about. thank you for your time. RR

Have a 340 10.5:1 340 run on 93 non-ethanol pump gas from Murphy
Full advance about 35°
No pings
9:1 should run on 90 non-ethanol no issues.