From what i understood to make this work you need to solder in a 1 k resistor to the coil trigger pin on to two of the coilpacks, IIRC its pin number 3 on the coilpack. ( if you only do one you only get half speed reading ). The remaining two legs of the resistor are then twisted together and a wire then run to the rev counter and it should work.
if you need someone to do this and are close to luton i have someone who can do it.
Faiser