I have a 2006 2WD Super Crew sitting on the stock 17's. Can I put the OEM FX4 20's with the 275/55/20 on my truck without a lift or level? Also, if so, how far off will my speedo be? Can I just pace it driving next to my wife for a while, or will it be off by different amounts at different speeds? Thanks for your help

 

Yes, those will fit easily. How far off the speedo is depends on the height of the OEM tires. And yes, it will be off more as the speed increases.

 

I went from a 2357017 to the 2755520 and on my trip this weekend the gps shows my speedo was almost 100% correct. Maybe 1-2 off.