1987 4X4 S10 blazer 2.5auto eng is over heating block is clear radair is clear took out theamstat still heating?????????????????

 

Does it have an electric fan or motor driven fan? If motor driving the clutch might be out. Its pretty cheap fix, and change the thermostat with a new one. Mine over heading when the clutch went out in TN on all those hills, and the owner be for me had the wrong thermosat in it..