[KingLT1]

These engines will knock even on 93 octane with the stock timing maps. I usually end up around 23 degrees on cars with intake / headers and 93 octane... which is about 1 degree less timing than stock. This is why they pick up so much power on E85. The LT1 picks up about 25-30whp on E85. The older LS3 will only gain about 6-8whp. I know you didn't ask about E85 but I am trying to paint a clear picture why octane is important for this engine.