I will weigh in just for fun. I will say that I have NEVER driven a stock FL350 except for a magazine test. But octane is octane. Higher test gas, be it AV gas, race gas, 92 pump gas, etc, will only help you if your
motor ((
Internal Combustion Engine ? )) needs it. In really simple terms, octane just helps keeping the gas from exploding too easily. The higher the compression, the more easily the gas wants to explode. So you need higher octane to keep it from doing this too early. Early detonation causes the dreaded ping and the eventual hole in the piston. Typically, octane will not do anything to keep it from seizing. That is something else altogether. (jetting, piston clearance, and oil). Typically, if your motor (( Internal Combustion Engine ? )) is getting really hot, you will seize it before you hole a piston. So if your motor (( Internal Combustion Engine ? )) does not need the extra octane, the extra octane does not do anything for you. In fact, in specific technical terms, it will decrease your performance. But it will be so small you could never find that.
But here is the problem that all of you are fighting. You may not know exactly what your motor (( Internal Combustion Engine ? )) needs, therefore running AV gas will be protection against the unknown. I have no idea what compression a stock 350 runs. We used to run up to 200 PSI on VP or Trick race gas. Around 150 will last on 87 octane. But timing and other motor (( Internal Combustion Engine ? )) design things also impact predetonation.
Oh yeah, all of this is based on sea level. Altitude will decrease the compression. And NEVER use octane booster. It does virtually nothing. We were short on race gas one night at a local track. So we used 92 octane in my race FL250 flat track car with that 104+ crap. My buddy was driving that car. I was messing around and following him on a flat track in my stadium car. I saw first hand the problem when it holed a piston and my own car shot molten aluminum out the pipe directly at my googles! (then I almost ran over my own car!)
So bottom line, anything over what you need is a waste of money. I laugh at people putting premium gas in their passenger cars so they will get better performance. It will not help unless their car specifically wants it, and has sensors and systems to increase the timing to take advantage of it.