M1 Single Plane Question

As far as manifold mods, I havent worked on an M1, but most intakes respond well to a nice fat radius where the roof of the runners enter the plenum, and they usually need a little help in that area as they come out of the box. Nice fat radius on the leading edge of the runner dividers too although that usually involves adding material, which most guys dont want to get into. But for sure, you can probably gain something by cleaning up the radius where the roof of the runners enters the plenum.