To those who have shaved the cylinder head of their cars - how much material was taken off...my head is being ported / polished / 3 angle valve job right now....I need to know how much to take off of the head ASAP - the machine shop needs an answer.

This is a street setup - daily driven - nothing that will put my motor at peril please. Thanks.

2003 VW GTI 1.8t.. I used to have a 95 Eclipse but well...water sucks.