Polaris 570 Side by side ranger. Overheating.

I am working on a 2017 polaris ranger 570. When I started on it it was overheating and engine just quiting. The temp sensor was bad causing no over temp light to come on.
I started checking it out to find out what was causing the overheating. When I removed the radiator cap and fill it with water it started pulsing water back out about every time the engine hit compression. So I said well blown head gasket. I took it apart and it had a blown head gasket. While replacing the head gasket following the manual I was torqueing the head bolts down in sequence small torques at a time. A head bolt stripped out before reaching torque. So I used heli coils to repair all 4 head bolts and while I had the cylinder Removed I found a broken ring so I replaced the rings. I also replaced the temp sensor, and themostat.
I put it all back together and fixed the blown head gasket. I let it idle for about 45 minutes to see if it would overheat. It ran for about 20 minutes and I keep a close watch on it the temp came up to the point the thermostat open and I felt the hoses at the radiator at that time the top was warm and bottom cold and a few more minutes the bottom became warm too. It ran anothe 25 minutes and the fan did not even come on until I turned ithe machine off then it came on for a few seconds. It was getting late so I stopped on it until this afternoon. I decided to drive it a while and see what happened. After driving around for about 15 - 20 minutes the temp light came on and the engine quit. I lossened the radiator cap and it had little water pressure and a little came out.
Now It has a new thermostat, temp sensor, head gasket, It is in time and it apears to be circulating water. So why is it overheating? I am at a loss.