1994 Jeep Cherokee Jeep Cherokee overheating

94 Jeep Cherokee 6 cyl 4.0l

I forgot that I had water in the radiator. One morning after a cold night I came outside to discover it had frozen a bit. Not too serious but still had some ice in it. The bottom radiator house was also disconnected.

I drained all the water, replaced the bottom hose and filled with antifreeze.

Jeep had no heat and was overheating so I changed the thermostat.

Still was overheating so I parked it in a heated garage for 24hours to let anything that might be frozen thaw.

Came back to it today and it was still overheating.

I took the radiator out and water seems to flow threw it fine. I flushed the heater core. I ran water thew the motor and it seemed to flow fine.

I hooked it all back up without the thermostat and it got to about 225 degrees and stayed there for about 30mins. I drove it to the part store, got a new thermostat and installed it. Filled it with new antifreeze and it overheated almost immediately.

Can anybody offer any ideas what it could be?

Also, it does not seem to be related to any head problems.