What cam are you using, going to use?
A larger cam bleeds of compression, as stated above. So, a 10-1 on one cam will be fine while the 10-1 on a smaller cam pings like hell. With 91 octane available, 10-1 is a safe range area. Also assuming you have a decent performance cam in there and not a stocker or a very mild upgraded cam.
My 360 small block is 10.82-1 and runs a med. size (
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