How nice would high octane gas be?

You're not in an exclusive club there, it's happening here in PA as well. The 455 Olds I built is running a cold Torker intake(meaning I welded cast iron plugs in the heads), & it
started experiencing percolation even running to the point the idle was unstable, the eng. temp was perfect. Those heads & intake were on that car for over 20yrs., 1st w/an
800DP Holley, & the only change was to an HP950 Holley up top. After changing to a new & improved block/cam & exhaust/carb, it ran awesome, & had only touched up My
valve-job on the ported C heads. The next season the trouble started, resulting in boilover after parking one day, & a consequential carb fire on a restart attempt.......... He
added a carb plate style heat shield & so far it has been livable, but remember, this thing ran the same heads & intake from around '93 on & this cropped up about '08 so.....
I believe He just ran it at a flashlight drag here recently, so hopefully that is all it will take to be OK, the hood clearance is tight on those early Cutlass bodies.