not likely, but they will reduce static compression ratio, you will need to calculate how much because there are different combustion chamber volumes for the 2T G heads.
Your cams will then be pretty much worthless with the new comp ratio (unless you are going to turbo it).
I would double check the amount of clearance that the valves have.
i ve got a set of 3tgte pistons half a mill over size do i still need to fly cut them?
my head is the later one please help?
please don't ask the same question in different areas, or we will be chasing all over the shop trying to communicate the same information see the answer that I left on your new thread.
Now you say later model head, which number is stamped on the front of the head (to the right hand side of the cover plate)?
Oh and remember valve reliefs are directly related to a) the size of the cams (and their timing) and b) the size of the valves.