Two “problems” I see with the proposed build of “750-800hp”.

The stock block and stage 6 heads.

The stock block will break(at some point), and the stage 6 heads likely aren’t big enough to make 750-800hp(unless they are the big Chapman’s).....without help from spray or boost.

If the goal is a “real” 750-800hp NA for a reliable bracket type build, I think the plan could use a few revisions.

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads