First off...
Welcome!!
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A turbo motor huh? It is a requirement that we need pictures. It's not written anywhere... but I'll hound you until you die.
Go ahead and cap off the vacuum line. If you don't have a provision for it on the fuel tap, you won't be needing it.
As for the fuel mixture, the richer the safer when doing testing. Lean conditions will be increased exponentially when the turbo starts forcing huge amounts of air in the chambers.
Are you running a single car setup or multiple? Here is where pics really help.
Again welcome to the forum!!!