The 3 or 4 TRD knobs I've tried to fit won't fit. The thread is correct, but the thread insert is too far up inside the shift knob. So when you try to install the knob you can't engage the threads. Although if it fits a Mk3 it should fit a Mk2 since the shifter is physically the same.
I bought a leather wrapped TRD shift knob on e-bay and it fits perfectly. This is the one thats all leather not the cheap one with the round thing in the top and then the rest is leather. Heck it fits so tight that its hard to unscrew.