Will the stock tach wire drive an aftermarket tach? Or do I need to run a wire out to the coil?

 

well iam assuming this is for your ef (iam a loser i read all about your car) there is only one wire in the whole tach system the blur wire from the coil to the cluster. so if you can run the wire anywhere on that blue wire wich is the stock tach wire. hope i helped.