Fuel mix for my 69 Camaro L78

[k92]

I run straight 100 octane turbo blue in my '70 Chevelle, w/o any problems. Original ls6 motor is gone,in place is a 396 bored .30 over, 11.5:1 compression,comp cams magnum 280 cam,stock ls6 intake/carb/exhaust manifolds,timing is 38 total,never over heats,but will ping if I try to mix the turbo blue 50/50 with 93.I dont know how some of you guys with stock high compression motors run 93 w/o any pinging unless you are really retarding the timing or your true compression is less than what it is reported to be.