You could have every guy on this site who plays around with motors come up with 1 or 2 plans for success in the quest for a 500hp 318....... but with no one taking those plans and following through with the proposed builds, it’s all just speculation.
There is no proof of concept.
Ported rpm heads(280-ish), victor intake with a bit of work, 12+:1, roller cam, 1-3/4 headers....... that would be how I attempted it.
Would I succeed? I think I would...... but without actually building it...... who knows.