Took just over an hour. The short stroke is amazing. I bought it because I often missed 2nd gear when racing. I learned how to toggle the stock derailleur before installing this one, but after reading the reviews I figured I needed a short throw. I'm not disappointed; got a scrape about 10 feet long on a strip of concrete in second gear and ran 12.86 seconds. 109.2 km/h. 1/4 mile The best time so far was 01/13. Got 255/55/17 on the rear/cold air intake and Hurst Competition derailleur otherwise a stock 2005 GT Mustang. On the other hand the Hurst shifts the same as my old '71 Torino GT and is way more fun!