99 Camry overheat issue

I just put a used engine down in the car for someone.. Old engine was locked up so i have no idea wat was goin on when it came to me. I changed all sensors an old thermostat from old motor to new block. Car overheats per gauge an gurgled a bit in overflow tank but not till gettin real hot.

Not gettin heat inside car
Fans not coming on when hot
Fans come on when a/c is applied
Top radiator hose gets hot,lower hose is cold
Radiator feels cool when temp is high. No bubbles from radiator except a lil Burp here An there like burpin air. When coolant gets real hot starts comin out radiator.
How do I bleed air out and how do I find out why fans are not comin on? And how can I diagnose why it's overheating?

Anyone??:confused:

Try replacing the thermostat with a new one.

Really ? because i like this car and very interested with this car