Muscle Car/Hot Rod/Racing 2-Wheel Drive 2/3-Speed Automatic Automatic 3-Speed C-4 Shorty. Replaces 13" tailhousing. Converts long shaft C4 to a short 4x4 version (That's 5 1/2 shorter). Muscle car applications with limited tunnel and driveshaft length. Install price - $850.00* *Typical install & drive shaft modifications. Does not include any modifications to exhaust, transmission tunnel or any other custom modifications that may be required.