Which 4x4 VSS wiring is needed for an LS swap keeping the NP241 transfer case?

Here is what the documentation says. Each point links to its source; details depend on your exact computer, harness and transmission.

• LS Control System kit; 4L60 / 4L80: The harness VSS connector must be attached to a variable-reluctance speed sensor typical of most late-model GM automatic transmissions. (Chevrolet Performance)
• TH350 / TH400 / 700R4 / 2004R: The SEN-01-128 fits GM transmissions with a 7/8-inch male-threaded speedometer cable outlet, including TH350, TH400, 700R4, and 2004R. (Dakota Digital)
• The SEN-01-128 generates a 12V sine-wave speed signal. (Dakota Digital)
• The SEN-01-128 operates on a supply voltage range of 8 to 22V. (Dakota Digital)
• The SEN-01-128's current draw is approximately 0.03 mA. (Dakota Digital)
• The SEN-01-128's white wire carries the speed signal to the speed input. (Dakota Digital)
• The SEN-01-1 is a GM transmission speed pulse generator producing 8,000 pulses per mile. (Dakota Digital)
• SEN-01-1 coupler nuts: sensor side 5/8-18, transmission side 7/8-18. (Dakota Digital)
• The sensor generates an AC voltage whose frequency and voltage level vary with drive speed. (Dakota Digital)

Confirm against the instructions for your exact parts before wiring. More: Tach and speedometer signals in our tuning guide.