Is this engine builder nuts?

Price sounds like it should be, especially with a roller cam and roller rockers, and the porting needed. We are pushing $5k, doing our own assembly work on a 340 with new Edlebrock heads, intake, pistons, cam, carb, and the usual parts, but no roller cam. So, your price may even be a bit low.....

If this guy is not a Mopar Specialist, I would go the route of new heads rather than porting the 920's. You'll end up with better heads. But then you need to see if you really want to spend that level on a smaller engine, of go with a lower HP and a less serious build.

The CR will help a wider RPM operating range...but that begs the question of what you are doing with this engine? Street? Daily driver? Drag only?