No problem!
Click on "Model", "Edit", "Main Rotor", "Governor", "Advanced". Be sure the box is checked for "Enabled". There should be 3 boxes that you can enter the head speed that you want (Low, Middle, High). Be sure the box is checked for "Enabled". Once you've done that, you can close that menu. Then go into your DX8 and in the Throttle Curve menu, set your low curve at a flat 30,30,30,30,30, your middle curve at a flat 60,60,60,60,60, and your high curve at a flat 100,100,100,100,100. I actually set my low curve at 0,30,30,30,30,30 so that at low stick the motor is off in Normal mode.
That's all I did to set it up and it works. Also, on the sim...turn on your "Flight Info" window and enable the "RPM" to be shown. It will show you the RPM and on most helicopters, you can even hear the difference in the head speed....just like a real rc helicopter.
I hope this helps!!!