I have a 67 , it had a factory tach that had the guts removed before i got the car- so not sure if it had a factory tach or not. i have a newer electronic dist with a tach output terminal that is not connected . I installed a new reproduction factory tach. it shows the rpm when cranking and drops to 0 as soon as it starts. the back of the tach is attached to the printed circuit only. Can i pick up the factory wiring and install it to that tach terminal?