The 250-4153 is a speed signal generator that goes in-line with a GM style speedometer cable, at the transmission. Simply unscrew the OEM cable from the transmission, thread the 250-4153 into the transmission, then thread the OEM cable on to the 250-4153. Produces an 8000ppm sine wave signal. The 4153 kit comes with a 7" speedo cable extension that has to be used. If you do not require the 7" extension, you will need the 250-4160 speed signal kit. Please call with any application or installation questions.
