Not enough octane? what you guys think?

hey guys,

went cruising with a few buddys of mine (none of which built their cars but have shops do it for them and so just blab what they hear) and they were giving me a hardtime about the gas im running my scamp.

the car is a 340 stock forged bottom end with .30 with old trq pistons that i beleive are the stock replacement style just .30 advertised at 10.5:1cr...the heads are stock x heads, and the rest of the setup is very mild as well...im currently running medium, which around here is 89 octane...i take the car to 6200rpm regularly and have no issues with pinging, although sometimes i get a lean pop or very slight hesitation when i tip in the throttle

anyways, that being said, these guys are telling me that i should be atleast running 91 octane gas in the car (one went as far as saying it will feel like it has nitrous....total goofball that one is) because the 89 is not enough...my reasoning is that if it isnt pinging then there is no point of going to the higher gas as i will just be wasting the unburnt fuel (higher octance burns slower i believe) but they say it doesnt matter if its pinging or not, needs more...91 isnt that much more expensive, but money is money...i for one dont even want to try it just to prove them wrong, but hell maybe they are right?

makes me wonder, should my daily driver run better with c12 in it? because thats pretty much what they are proposing

whast do you guys think?