Which of these is the right tach driver circuit for a 96
 

I don't have a tach signal with my standalone 96 MSI 3.0 install. Can someone advice which of these circuits would work? thanks.

http://www.msextra.com/manuals/MS_Ex...l.htm#tachoout

The first one, labeled "A low voltage tacho out..." with only one resistor, should work. The stock tach signal on the NA is just a simple 0-12v squarewave (might be 0-5v on the ECU-driven cars) that goes high once per ignition event. It's not a very finicky circuit in terms of duty cycle or exact amplitude.