I have a 90 vette I changed the thermostat water pump and the engine still gets hot and overheats I've run out of options in my head to figure out what is wrong other than Maybe I may need to flush the engine possibly due to a blockage does anyone have any ideas

 

Make sure the fan turns on at the proper temperature. Check for possible blockage between the A/C condenser and radiator. Make sure all of the factory seals are in place.