1968-1971 Ford Thunderbird, Lincoln Mark III. C6 Automatic Transmission REAR OUTPUT SHAFT. This is an ORIGINAL FORD PART. Removed from a 69 Thunderbird 429-C6 Transmission. 31 Spline Output. 25-34-36-31 spline. Measures 23" Overall Length. The Shaft is in Great condition... No Rust. No Visible Wear. No Chipped Gear Teeth. Has Great Splines and Gear Teeth. Overall, this is a Great Original C6 Transmission Rear Output Shaft. Please email with any questions. 071414 WE HAVE AN EBAY STORE WITH THOUSANDS OF ORIGINAL and NOS FORD PARTS. CHECK IT OUT.