in this image, we are looking in from a different angle; and can see a bit more of the passages intersecting. The very shiny surface is where I have started to grind down the excess iron at the bottom of the transfer pipe passage in order to get rid of that step. My long shank carbide burrs worked very well in this situation. I opened up the intersection, and radiused the short side radius of the turn into the main passage, to promote smooth flow.