Inlet Outlet Plumbing of Cast Iron Radiator

mycoleptodiscus

I'm reinstalling a large, long, low cast iron radiator in the kitchen.  When it came out, it was plumbed bottom in, top out, both on the same side, with large diameter iron pipe.  Now its old branch circuit has a circulator pump tied to in floor hydronic, a small radiator in the 1/2 bath and the large radiator in the kitchen.  1/2" PEX with a 40' total run of pipe to the lg. radiator, 20' to the small and several hundred on the floor heating.  I have globe valves on the two radiator circuits to help balance flow as the floor heating branch has the most resistance.  The small 1/2 bath radiator really pumps out heat.  The kitchen radiator  gets warm on the top only.  The water appears to flow in the bottom and right out the top without passing through most of the radiator, even when the other two parts of the branch (floor and 1/2 bath) are closed.  There's plenty of flow volume as I can run water through just the kitchen radiator branch on the circuit and it flows like a garden hose.  I kept the bottom in, top out, same side configuration.  I'm thinking I should change to bottom in, top out, opposite side to get some flow through the radiator.  Thoughts?