3 pins on dizzy, 2 on lead from coil?

I have a '93 RRC which I ordered a new dizzy for. When I took the old one out I noticed it had only a positive and a negetive terminal going into it. But my new one has 3, I have been led to believe the one in the middle is an earth - I have found I can get a convertor lead for 20 quid, but can I just leave the earth one out, or connect something else onto it and just match + to + and - to -?

Yeah out side terminals are pos and neg.... middle is additional earth - body should earth not really esential, but a good idea anyway. + and - go to coil +&- not to batttery.

Good guy to speak to is:

V8 Rover Lucas Electronic Kit 35D distributor TVR etc | eBay UK

Ask for Simon - he has enployed a couple of ex lucas guys to take chinesse repro castings and rebuild with lucas guts - end product is great!!!! have used a couple of dizzys from him and both have been really, really good. You can get a lead from him....