I heard there needs to be advancement in timing with tools such as cam timing disc and a micrometer gauge to spec on the cam. The comment on that forum said 1* retarded every 0.010".
http://brickspeed.net/forum/showthread.php?tid=1845

I saw many of guys on this forum with new head gasket and milled head saying fine.

What needs to be done? Do I ask the machinist how much he would scrap off?
Would the conventional belt adjustment method on Honda manual just finely do?

In the midway of head gasket removal procedure.

 

If you're jus doing a resurface on the head (0.010" or so) I wouldn't be worried about you cam timing.

People allegedly start having issues when they mill like 0.040" off. As far as I can tell from my knowledge of how pulley and belt systems work, it shouldn't affect cam timing if you mill a head.

If there's no slippage or slack in the belt the motion of the cam gear is determined by the ratio of the diameters of the two gears. I'm going to guess the reason people have issues after a big mill is how much the compression ratio is changed. The easiest way to remedy having too high of compression is to adjust the cam timing to "bleed off" some of the air in the cylinder.

Hope this helps!

 

kind of. when you have a piston coming up to TDC before an unmilled head or block you change valve events. degreeing puts max lift events back to original cam spec.