YOU'RE MISSING OUT IF YOU DIDNT REGEAR! 

Put some nice big tires on your truck and now you're wondering why it's so slow or wondering what axle ratio ring and pinion you should choose when you regear to fix it? Then this is the video for you. You can also accomplish speedometer correction by choosing the axle ratio proportional to your OE specs. Simple way to calculate best axle ratio for big oversized tires. Can also correct speedometer
1999 2000 2001 2002 2003 2004 2005 2006 2007 Excursion Superduty F250 F350