5.02 does work. It just makes your GT act as a Pro xD. But the performance is the same as it would be with the new driver. You just lose the horn button, the red turny knob thingy, and that +/- button thing. In fact, I played LFS for 4 months with my DFGT on 5.02 before finding the new drivers. You still have the Logitech Profiler (the program that gives options for Wheel Rotation, FFB Strengths, Centre Springs, the works.
If it is turning to quickly... yeah, set it too 720, and have it calibrated again to find the locks on the wheel. (This can be achieved through un/re plugging in the USB cable or by rebooting your computer). And make sure to have your in-game set to 720 degrees to ensure linearity.