Sometimes it's tricky to burp all the air out of a 4.0
Simple trick - right at the front of the head - driver's side, there's a stud sticking up. That's a headbolt - it runs through the water passage. Note that the engine is slightly higher in the front than the rear, if not, jack the front up till it is. That will become the highest point on the system.
Remove the headbolt - when it's cold, not hot. Fill the radiator till water runs out the headbolt hole. When it does, wait a moment. Repeat until it stays full. The air will come out first, then coolant.
Replace the headbolt, tighten it to the headbolt torque. It's solved the bleed/ airlock problem for me several times.