I'm putting together a build for my z6, upgrading from my hf/14b kit. I'm using a .60/.63 thunderbird turbo (super 60?) and will be getting a set of brand new vitaras from FJT once he has them back in stock. I'm kinda concerned about the compression with a larger turbo, but I've heard of people modifying 3 layer y8 head gaskets by removing a layer yeilding roughly 9:0:1 or something like that. Can anyone elaborate more on this, which layer would be removed and how I would go about doing with without comprimising the sealing of the headgasket???