Cast pistons are very brittle. A engine that could/ would see that kind of boost will certainly experience some type of detonation. Detonation would tear cast piston ring lands off in short order.
I do have nice forged 250 and 292 pistons available on my website.
Inliner Member 1716 65 Chevelle Wagon and 41 Hudson Pickup Information and parts www.12bolt.com