Re:G-tech says I'm in the high 14s, Ya hoo!
 

According to Richard Holdner, it does matter.

Why mill the head? To get higher compression or a flat deck surface.

When milling the head to achieve more compression, just a few thousands of an inch make a large difference in output power.

The small amount of removed material shortens the distance from the cams to the crank pulley thereby causing a slight retard of the cam timing.

How do you correct for this?...Adjustable cam gears.

Some cases may require this solution.

Can you get by without them? Probably so, but why not have them anyway?...When applied correctly, they are proven to add horsepower (even without a milled head).