Has anyone ported stock magnum heads and have the before and after flow numbers .???

IMO, It’s ether the replacement cast iron head or the Edelbrock head if you want to stay with the Magnum set up style.

Honestly, for the street, the OEM head and the cast iron replacement is fine. Ether run the OEM head stock or upgrade to the replacement head and run that as is or ported to suite your target goal. The Edelbrock head also falls in with the aftermarket iron head. Same deal, as is or ported. You can get pretty far with the chink or Edelbrock head on the street or make a good bracket car with them.

Replicarracer43 stated 270 cfm @ .500 lift. That can make for a real good street car, no doubt. It would even do well in a bracket racer set up.

After that, forgeddahboutit…. Move to a more serious LA head.