What causes my temperature to rise 3/4 the way before fan turns on

Good morning, I hope this email finds you well, I am contacting you today in hopes that you can enlighten or give me your personal opinion. I own a 1994 Plymouth acclaim and I just bought a 1991 Plymouth acclaim that was sitting down without being driven for 13 years. I replaced all the fluids, but the car temperature keeps rising to 3/4 before the fan turns only when the vehicle is parked or stopped in traffic. I had a new radiator installed, new water pump, new radiator cap, new thermostat 160 degrees, had both temperature sensors installed new, a new radiator fan relay, and bled the system. The car runs great and it keeps cold when driving on highway, but my concern is that the temperature rises to 3/4 before the fan turns on and it cools the engine. Also the I had a mechanic check the head gasket and he said it was good as there was no white smoke coming out of the tail pipe, no water was on the oil, and it didn't have that many miles. The reason for my concern is because my 1994 Plymouth acclaim temperature never rises above 1/2. Do you happen to have any ideas on what the problem could be? The only possible thing left to do is to change the fan, but the fan does turn on with the AC on, and on its own just it waits till the temperature rises to 3/4 the way. Thanks in advanced for all your help.