Step Right Up and Guess... What will my 410ci make for Power?

My previous motor (may it rest in pieces) was really close to what you described (410 cubes, 57cc ported Eddys, dished Diamond pistons, 10.8:1 compression, 248/254 street roller, Airgap (and /victor...tried both), 750 Holley) . I never dynoed that motor, but it ran 10.7-10.5 depending on the weather.

Should be between 530-540hp (depending on the dyno). My guess is 539hp....just for grins.