Ok so I have a motor that I got out of another car I bought. It's a 355. It will run hot as in 240ish anytime you aren't doing a constant of about 45mph. I pressure tested the cooling system with no pressure loss. I replaced the water pump with the correct rotation pump. The radiator is a two or three core aluminum with a single electric fan. Thermostat was completely taken out. Air dam is under the car and in tact. I don't know what else to do but I am getting really sick of it. Oh and the oil doesn't look milky. Any help will be much appeeciated.
Oh the car is a 85 camaro.