Need help. I’ve read everything on this forum. Mule is still overheating.

replaced the following:
thermostat
water pump
head gaskets
radiator cap

fan works and switch is good.

I have pulled it up on car ramps to bleed it multiple times. Let it sit overnight bled again the next morning. Bleed screws have antifreeze at them and radiator is full. Drained entire system and started from scratch. Filled the system with a total of 5L of antifreeze. Still every time I run it there is air on the return side and pressure is built at the supply side. No flow and the hoses at the return side do not get warm. Not sure where to look next. Help please