What I would do...
After reading a lot on the subject and flying piston singles for a living, this is what I do. For CHT, set 400 degrees as your max limit with a warning that goes off at 380 degrees. Cylinder life will be much improved if you can always maintain less than 380F on the CHTs. For EGT, the exact number and spread between cylinders is not important. Depending on probe location and a variety of other factors, EGTs may vary as much as 200F per cylinder. That being said, on mosty Lycoming engines you probably wont see more than 1500F at peak and you cruise EGT can be anywhere from 1200-1400F. Hope this helps. Read some of Mike Busch's articles in Sport Aviation about this topic. Cheers.
