you need the sensor and the black shutter that go on the rotor arm's rotating poll in the dizzy. guess it could be worth it if u can find a way to scrounge half a system.... What kind of rover you got there?...I'm a big rover fan myself...suprising since I've been screwed twice w/ my range rover experiences! Ryan Z. '76 2002 ex '87 RR and '89 RR