Another overheating situation 63 Slant six

Well, the thought was to try timing early, on-time, and retarded to see if there were any difference, there was not.
Ill try the rumble, rumble (Im a tank!) suggestion.
As far as the coolant flow, I currently have the thermostat out, as another test for the problem. There is a ton of movement.
Now this am I went out and with air temp of about 60-65, I started the car in the driveway and let it warm up at idle, after 8 minutes the temp was up to 220 so I shut it down. The fan had come on around 200.
I waited till the fan stopped and popped the cap, still mostly the same amount of coolant as I started with as I didnt let it blow off any. I decided I would drain the radiator and pull the bottom hose and run water through as suggested earlier.
When I removed the drain petcock at the bottom of the radiator and catch the coolant I was pretty stunned to feel very cold water coming out of the petcock. I checked the water at the top with my finger and it was still hot but the bottom water was cold, seemed like a huge difference. So it sounds like the radiator is hosed but I asked for advice, what you think?.


Thanks
John
Sure sounds like there is a blockage in that radiator. If you squeeze the bottom hose, do you see movement in the water at the top? After running the engine, is the bottom hose hot?