Brainstorming an Idea, whats your 2 cents

I would replace the pistosn with forged if a sonic check shows it safe to go to .040 over, or if the bores are in good shape and with just re-honing you can keep the piston to wall clearances close. I dont use factory rods with 4" cranks. The heads will limimt your power by a bit. Magnums have a purpose, but a small block over 400" just isnt it. To be honest, you have a nice solid combo...Why not just add a decent cam and headers to it, maybe a single plane, and run it that way? The heads will make 450hp or so maxxed on a 360. They will make 450 on a 408 or 410 too...But they will be out of breath early and you could make a bit more with better heads.