If you surface the deck of the head and block during a rebuild, is there a general rule of thumb one could expect? For instance, machining the head/block will cause cam timing to be retarded (or advanced) by "x" degrees, and you'll need to advance (or retard) both intake and exhaust by "x" degrees?

I'm degree'ing my cams in now after a fresh rebuild, and both need to be advanced by 2 cam degrees. Just looking for confirmation that this is what should be expected.

 

anyone have direct experience on changes in cam timing after machining the block deck or head?