Originally Posted by volaredon

calibration not needed for the size of the WHEELS...… but overall tire height. You can buy 15s,16s and 17s for the respective wheel size that are all exactly the same overall height which is what matters for speedo calibration. If you want 22s you can find some kind of thin sidewall rubber band tires that will work fine with the speedo calibration as is.... NOT that I would suggest doing so, unless you want to completely ruin the appearance of your ride

Originally Posted by dybeepvw

Hi dodgemahal, I just purchased one like yours, 1998 SLT plus, 4x4, 5.9L, White with gray interior in really great shape; mine has 17" wheels with 265/70/17 tires and speedo has been calibrated for the bigger wheels. It really runs strong; has a power steering hose small leak, and a few small drips from oil pan, so have to figure out if its pan gasket or rear main or valve cover gaskets or combination of all.