I am just got done breaking in my new motor which is a 383 Tuned Port Injection. All the sensor data looked good, A/F ratio was right at 14.7 and water temp was around 200F.

At about minute 15 my stainless block hugger headers started changing color. At minute 20 at 2000 rpm, the headers were glowing red. I took a infrared thermometer to them and they were all within 15 degrees, around 375F.

My question.....What range are these headers supposed to be running at? Makes me think the motor is running lean but the 02 sensor says everything is good.

Any suggestions or comments?