It depends on what the problems are with the handling. I'm no tuning master by any means, but generally I can help, if at least a little.
For the understeer, I'd just say soften the front a bit, and if you really want to, increase the rear spring rate. Also, make sure you double check your LSD, as if it is too strong it will make the car understeer a lot. Also, reducing rear toe could help, but I still need to experiment with that a bit more.