Most inportantly, are you looking for more steering while onpower or off, entering a corner or exiting? I didn't quite figure exactly what you were looking to change, that should help us narrow the suggestions.
Also, you are changing your setup from a ___? to a solid front axle rubber tire setup?
Modellor made excelent suggestions, but the rear toe-in suggestions won't work for everyone on every track. I prefer to start with 2.5 degrees, doesn't matter too much, though, as toe-in is an easy change to perform trackside.