Why don't you just copy my engine? I have a 512 inch big block in my '65 Coronet with a Doug Nash 5 speed and a 3.23 rearend gear.

The engine made 575 hp on the dyno, 485 rwhp on the chassis dyno and it runs on pump gas. The compression ratio is 10:1, the cam is a hyd roller with 246/246 on 112. Heads are CNC ported, intake is Trick Flow, exhaust is cast iron manifolds and I'm using a Holley Sniper EFI system with Hyperspark ignition. I think it checks all the boxes you want checked. Figure on spending about $10,000 to get an engine like that built. Here is a video of it on the chassis dyno:

https://youtu.be/xG3-_YJGdZ8