I purchased a 4 post lift and told the supplier I had a 01 Chevrolet 3500 DUALLY. I paid more to go to a lift that would be long enough and WIDE enough for the Dually to fit. After building the lift I found the space between posts was not wide enough for the rear fenders to clear. I called and questioned how they could say a Dually would fit this lift. NOW for the rest of the story.......They had purchased a 2011 or 2012 RAM Dually and said it would fit just fine. I asked for the dimensions from outside rear fender to outside rear dfender and the tire dimensions from outside tire to outside tire. They came back and said the RAM Dually fenders were 10" overall less than the 01 Chevrolet Dually. Unbelievable! I then started to check and see what dimensions I could find for various vehicles to check these dimensions. Seems everyone wants to sell them but don't have much interest in publishing the info to compare. Does anyone now where I can get this dimension other than going to the local RAM store? Frustration runs high and I have already beat myself up for not checking this before hand.