RE: GS SUT PRO
That would not have been Don from DHN would it? I don't know him personally, but we've raced against him several times. he's always tough.
I used 7KF 100KC 3 or 1KR depending on what the individual wanted. If you don't use a very heavy center diff the front wheels will unload at high speeds and coming off corners. One of the guys has dropped his center diff to 60K and likes it. We tried 50K and it was too soft so I would say 60K for the center would be a good starting point.
The more diff action you allow, the quicker the driveline will unload to the wheel with the least amount of traction. The lighter the diff oil the more diff action you get. You can sim your diffs up tighter that usual, but it will only accelerate wear.
Another thing that helps tire unloading is stiff foams in your tires. ProLine supplies Bowties with foam that is far too soft for racing. Trinity or Panther both have excellent foam for racing.