Chevy guy trying to setup a mopar. Second attempt

Yes, his engine builder is going in the right direction, lord knows why he didn't go this route when the engine was stroked. The cork in the mix is firstly the heads that need to be opened up and then going to a hotter cam with a lift in the .570 lift range would be in order (he's still driving it on the street right). The other alternative is spend a little more money and go with the 440 source http://www.440source.com/ aluminum head if they're back in stock that is. The cam in that 440 right now is basically the factory cam for 440 6 packs.
Personally I'd talk to Hughes Engines http://www.hughesengines.com/ before nailing down the cam and head combo.

I'd also recommend minimum 850 cfm Holley or Demon and a Edelbrock Performer RPM intake.

Terry