I have run some tests and consistently the left is 30 degrees hotter than I set the temp to, the middle is 50 degrees and the right 60 degrees. So if I set to 220, it cooks from left to right at 250, 270, 280.
Couple of ideas I have thought of that I can do to help with it:
1) always try to cook on the left grill grate and rotate food to help even out temp ( can't do with large load of food)
2) set temp lower than I want so the middle is correct, left is lower, and right is hotter. For example, when I want 250, set to 200, temps would be 230, 250, 260.
Any other techniques others have used? any other modifications that can be done?
I should mention that I have the Don Godke downdraft installed and the vent is closed because I am always cooking under 350.