What is the largest tire size without a lift kit for 2006 Ford F-250 Crew Cab 4x4?

The largest tire size that can be installed on a 2006 Ford F-250 Crew Cab 4x4 without a lift kit is 35 inches. However, it is important to note that this tire size may require some minor trimming of the fender wells in order to fit. Additionally, installing larger tires without a lift kit can affect the vehicle's handling and performance, so it is important to consult with a qualified mechanic before making any changes.