That's the one Rob!
How many wires does that one have? On my SL (with '91 GTC SBEC harness), I have a total of 39 circuits to splice there. My SL doesn't use all 50 pins because it's an '87 when things were simpler and due to option content differences between the SL and GTC.
I don't have much in the way of extra pins though, so as long as it has close to that I'm sure I can make it work. Heck if I can find two of these I just might make a TIII harness while I'm at it.