if you have the complete zetec it would be far easier to use "hybrid edis4" as found on mk3 fiestas etc (red module with built in map sensor) And then you can carb the zetec. the edis only requires a live and earth, and is a far more modern and reliable ignition solution than your distributor, building a zvh is reasonably in depth, bolting the 16v in and adding an edis module and carb is far easier, and ultimatly more powerfull and reliable, although not without its technicalitys of course, but then you wouldnt take on a project like this if you didnt like a challenge!