Ah, when you called it a coilpack, it sounded like a CA18 or something...

Do you mean you have 2 negaitve wires in the loom or are there 2 negative tabs on the coil?

The positive of the coil connects to your ballast resistor (required for the R version of the GT40s) and 1 negative goes to your points, and the other to your tacho (if you have one, otherwise just leave it off).

I can't remember the wire colours at the moment but if you need a wiring diagram, there's a 1000 coupe owners manual on my website below \/ which should be 90% correct