I remember hearing somewhere that turbo motors work best by torquing against taller gears (like 3.27s) for longer periods as opposed to revving fast and dropping RPMs (and boost) in quick succession like you would with lower gears like 3.73 or 4.10.Maybe a turbo expert could correct or confirm this but I'd look for on with the 3.27 ratio,especially with a long stroke slant 6.
