Octane rating..Circa1970

[TDW]

Well, that explains why the fresh, 11.2 to 1 350 LT1 doesn't like the 93 gas. We broke it in on the dyno with 110, then tried to run some 93. No go. It rattles. We played with timing and jets quite a bit, different heat ranges for the plugs. I thought the Premium, or Ethyl, back then was closer to 96 or 98. I read on a bunch of different sites that guys are running these engines on 93, so I wanted to try it. My L78 and my 302 both will run on 93, but they seem to run better when I mix the 110 with 93. Thanks for all the responses. Hope to have the engine running in the car in a day or so. Can't drive it yet because of the salt and snow, so no real hurry on it.