To Zipper: you will find the coils-2 under the hard black plastic screwed down piece that is right on top of the camshaft cover. The green wire might go to coil ground but don't depend on it. What do the instructions indicate?
I lack a tach in my '99 Sephia and was told that it would be better to replace the entire dash assy with one that has a tach. This sounds a little iffy to me. It would look best though for resale. Where are you going to mount your tach? Let me know how you are making out please. speedster1