Originally Posted by BOETJE
Yes you do .
If the timing marks line up , like he said, then it doesn't matter how much is milled of the head. Thing is that if you mill a lot off, you might have to slot the cam sprockets in order to make them line up.
The timing marks only get it lined up to the right chain tooth. Once you add a variable of machining the head, you need to degree the camshaft in.
The timing marks are on the sprocket so slotting it won't help. The marks might line up, but the cam could be anywhere. To get it right you need the timing spec of the cam.
For what it's worth, Megacycle make a couple of cams for that bike and they have 108 degree lobe centres. That might be a good starting point.