just snagged a wire out of our robotics room today. probably about 4 gauge. i just put on two "O" type connectors (ones made for bolting) and wrapped it with electrical tape and a ziptie, cause i know that tape comes off. i need to get some heat shrink some time. anyways, im going to run that wire from the starter terminal lug up to the engine bay, where I will attach the MSD ignition to, to power it, and the engine bay mounted tach that I am planning to install. i want a tach so that I can tune the idle and not have to look at the in car mounted tach while doing it (it is a PITA). yeah, so im going to get a tach that works with the msd ignitions and run a "Y" off of the msd tach output wire and that should provide signal to both tachs.
Its a street/ track car, and im planning on adjusting it richer whenever i go to the track or hit skyline road for those late night street sessions, to make more power, and then run it leaner during the day for better drivability and gas milage (the engine bogs when running right at low rpms).