Bill,
Can't say as I've looked when I had my Alternator off, but the newer 4-cyl models have the oil pressure sensor tapped into the top of the block below the Alt. I think the WRX guys put in a "T" for the pressure sending unit.
I would assume the same (putting in a "T") for the coolant sensor.
the thread below says pin 16 of the 16 pin connector at the ECU has the tach signal.
http://www.subaru-svx.net/forum/show...threadid=16843