Resurfacing head for metal head gasket

[Rick Frey]

At 11:19 AM 12/8/2002 -0600, Jay Stewart wrote:

>Also, MLS headgaskets usually aren't the same thickness as stock. Make
>sure you know how much your block is decked, head shaved, and the
>compressed thickness of your headgasket of choice. Changing this will
>change cam timing, and you will need to correct for this.

I am trying to figure out why different gasket thicknesses change cam timing?

Is it just some distance difference from the gear on the crank which drives
the timing chain and the cam gears?

Or, is the change in combustion chamber volume such that as the piston
travels down to create vacuum this all happens slower due to increased
chamber volume?

Or am I way out to lunch?

TIA,

rick frey