If you would have had that much detonation, the spark plugs would have told the tale. Check #2 plug for aluminum embedded into the end. The #2 rod bearing will probably also be hammered if detonation was the cause.
I think you had something get into the combustion chamber and then was bounced around.
If you're looking for more power, now's the time to upgrade to a stroker kit.
I also offer complete short blocks and ship to Australia....