LA Block/Magnum Heads
Ma MoPar's create engine, the 360/380 HP, has constantly dyno'd north of 400. They used a 288 intake duration roller cam. I suggest this or a slightly beefier cam. The heads were stock as were the Magnums slugs. A M1 single plain was used along with a 1-3/4 tube header and *I think* 750 carb.
Contact MRL for a roller set up. He has drop in lifters tha are excellent and is wise enough to select a cam for your plan.