On aftermarket(pro comp) 20" wheels - 8 bolt by 170mm I was told they will fit ALL 1999-current Ford Super Duty trucks......is that true? I thought there was a difference from the 1999-2004 to the 2005 and up?Thanks alot.

 

The bolt pattern is the same for all of the Super Duty trucks... 8X170mm. However, the amount of back spaing is different depending on the year of the truck. 1999-2004 had leaf spring front suspensions and need less back spacing. The 2005-2010 have coil spring front suspensions and can take more back spacing.

What specific wheel are you considering? The Pro Comp PXA6006 wheel in size 20X9.5 has 5.25" of back spacing. I don't think that will work with the 1999-2004 Super Duty trucks.

Pro Comp Series 6006 Chrome Wheels - Chrome Jeep & Truck Tires, Xtreme Alloys

 

2005+ trucks have more offest to the wheels you will need 5.5-6" back space on 05+ and 4.5" back space for 99-04 wheels.