No you cannot use the edge to switch EFI tunes on a LBZ. LB7 and LLY you can but not LBZ. If you want on the fly EFI tuning you will need to use the DSP switch. Lots of EFI AutoCal kits out there with that capability. Or find a shop to work with and use their tuning. Your edge will work just fine for monitoring but wont be able to change tuning. From what you say the PO said it is already tuned by very likely EFI.