I have for sale a TS Respeed. It will adjust your speedometer so it is correct when you had bigger tires and/or change gears. It is very easy to install. I bought it and was gonna use it but decided not to put it in. It will work on any 1992-2006 F250 or F350. It costs $300 new and I would like to get $250 for it but I will take offers.