IIRC, they sell the Iron Eagle S/S heads.
Those flow nearly as much as Vortec heads, and according to CHP, they made about the same HP and Torque as Vortec heads, on a 383 using a Comp Cams Xtreme Energy 274H cam.
Look at, not only the peak numbers, but the average numbers.
Here are the results of the Dart heads.
Then the Vortec Heads.