The reason it has two of each terminal is that it was ORIGINALLY a LANCIA PART, and probably just used a seperate connection for as said rev counter or supressor.
Despite what some say it is a LANCIA part first and foremost in that it was oe kit on these first not specifically designed for cossies.
A lot of the sensors are shared with a lot of the cars that use webcon(weber marelli) management, like the fiat range that uses and almost identical ECM to sierra cos 2wd.
tabetha