I picked up a new to me 06 YZ450 last fall and have spent some time this winter going through it. I'm quite happy with the state I have the bike in now except for the header. When I first got it I had noticed the header was quite close to the coolant hose going into the pump housing. I figured maybe it was just rotated down. Since then I have gone through the top end, changed the header gasket etc and tried to position the header farther away from the hose but when I tighten the header flange it seems to settle it back to the same position.
I have been looking at pictures of other 06's and in comparison my header appears to not extend as far forward as others, and possibly the radius of the bend is smaller. I really don't think it is bent but is it possible it has the wrong header on it? I'll attach a picture (hopefully), so you can see what I mean.