A SGI-100BT isn't needed any longer...
You can either change the tune, or adjust the pot on the Toyota Tach to accept 4 pulses/rev.
Either way, you might also have to use a pull up resistor, or remove a resistor on the tach if your ECM outputs 5V pulses rather than 12V pulses.
I wrote more on the V8 thread, and my build thread.
You can either change the tune, or adjust the pot on the Toyota Tach to accept 4 pulses/rev.
Either way, you might also have to use a pull up resistor, or remove a resistor on the tach if your ECM outputs 5V pulses rather than 12V pulses.
I wrote more on the V8 thread, and my build thread.