Filled up trans with Syncromesh. Even though the G56 calls for ATF, Southbend and others reccomend Snyncomesh due to its thicker viscosity and cooling properties.
Then I got to work on the Reverse light switch. Problem there is the plug is unique to the G56, I don't have it, and it is unavailable via both aftermarket and dealer as of now.
Finding a yard willing to cut off the plug from a good harness wouldn't be easy (or timely) so I put some very small female spade connecters on some wire and pressed them in.
Since the spades are so close to eachother (less than half a mm) I filled the cavity with silicone to keep them in place and protected. The G56 reverse light switch sits about two feet rearward of where the 4500 one was, so some extensions with spades were necessary. I plugged it all in and it worked great!