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1966 FE 390 Running Hot

Just put a rebuilt FE390 with 5K on it into my 1969 Mustang. It is running at about 230 degrees. Any suggestions to lower the temp. Timing?

Electronic Fan install?

Was the radiator sized for the 390? Is this a rebuild of the factory installed engine?

If the radiator is not big enough for the engine’s needs, this will happen.

The radiator I am using now came with the motor. Motor Trans & radiator came out of a 1968 project the previous owner never finished. It is a good sized radiator. It is not aluminum but it is very light. I have another radiator that is very heavy and I think it is original from 1969. My Mustang came with 428cj. I will measure the sizes of the radiators. Do you know how to tell how may cores a radiator has? 3 core 4 core does it matter?