430+hp 340 possibilities

Yikes! That’s flying!!
He would know, he built my heads. I’m at 410 CI and 12.2 to 1 so not really street friendly and I’m at a little under 400hp. Now my motor is pretty underperforming due to having to run stock 68 intake and exhaust manifold castings. The intake is somewhat modified. As to cost, not crazy, but to build it again, $10,000?