Octane requirement question

Problem is I don't know what to listen for, I've never heard pinging or detonation.
And the exhaust on this truck is pretty loud, specially in the higher rpms, so I don't think I'd be able to hear it if it was going on.
I just figured I could ask if theoretically this engine could be ran on 87 octane given the higher altitude and the compression ratio of 9:0.1 and the cranking compression of 150 psi