What headers?
I can understand them voiding the warranty for grinding on the box. You modify it, you own it.
Voiding the warranty for an adjustment seems kinda lame, especially if it wasn’t adjusted properly to begin with. But looking at it from their side, if you adjust it incorrectly it will cause abnormal wear. So I see where they have a point. I suppose the right way to do it would have been to inspect it first, that way you could have sent it back when you discovered it wasn’t adjusted correctly as shipped.
