Unless the motor was designed intentionally to run on high octane fuel, there seems to be a mismatch between camshaft & compression ratio. These things can be fixed, for the price of pistons, rings & gaskets.
Flat top pistons in a standard displacement short block & C302 heads should yield 9.5 to 10.0 compression ratio. With any kind of a performance cam, that should not be too much compression for 92 octane pump gas. So I would expect to see pop up pistons in your motor, or a stroker crank with flat tops.
George
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