I think it would have to have the chevy stud spacing to use the chevy shaft rocker system. Not sure how much difference there is between the magnum and chevy, if any. The valve spacing between the two engines are within a few thousands. There are a few different shaft systems I saw in a quick search ranging between .150 and .775 offset (the .775 being t&d). Yes I would propose raising the port, I believe Johnny mentioned raising the port 1/4 inch, this would put the port close to a w5 port floor location, and as long as the intake faces of the head were moved towards the center of the block the correct amount you would be able to use an la or magnum intake. The only caveat to that being you would have a larger gap at the front and back of the intake to be filled by a spacer. I posted a picture of an my la super victor intake sitting on my W5 heads on a 340 block earlier in the thread.
For a bigger port (cnc?) Head I would propose moving the pushrod out of the port to gain csa and volume, hopefully something around a 230cc which would require the offset rocker. To put it into a nutshell, something similar to a W5 without all the exotic/expensive race parts, would be the "cnc" offering. Standard pushrod, standard chevy stud rocker, the "basic/standard" head.