Paul,
Does the engine pull well up to 3,000 and then just flatten out and start to miss, or is it sluggish getting up to 3,000 under load? Also when you are just running it under no load. does it act the same way? That # 3 plug really looks as if it isn't firing at all and if they just ran the engine to break in the cam and not under any load, then it must have came from them the way it is unless you have added or changed something. I believe in an earlier post someone asked you if you had checked the valve springs as some engine builders use a light set to do the break in run with and then put the heavy ones in for the dyno and testing.
Ron
