[Fot] How far can a GT6 head be milled?

[Jason Sukey]

I'm getting ready to mill the head on my GT6 for a bump in compression.  I
currently measure 3.255" thickness, my math shows that I want to end up at
3.215" when I'm done.  I can't find much info on how far people are safely
milling the GT6 version of this head, only TR6 info.  Does anyone have
experience on this?  Is there enough meat in the casting to remove this
much material without hitting water?

Thanks,

Jason Sukey