Turbo....

I know a good bit of theory with turbos. Forced induction. Not difficult to understand. But I have a question for some of yall who've tried or run turbos on slants now. What's a "safe" static compression ratio? Is 9.5 too much? 9:1? I've not ruled out making my current build a turbo build. Keep in mind this will be with the factory prototype closed chamber head that will have some quench. That will be "however thick" the head gasket is. I have head gaskets ranging from about .018" to about .045" compressed thickness. Compression with the thin one will come in at about 9.4. I know some will depend on the camshaft too and how it can limit cylinder pressure. Thank you drive through.