I have exchanged my wimpy 235/75/17 stock tires with 33/12.50/17 tires. My truck wants to shift to overdrive at 60-65 mph but any acceleration it wants to downshift. If I am on any sort of incline or have a head wind the truck just continuously runs in 3rd gear. It will not even go into overdrive. It will not shift gears until the RPM's are around 3000. Is there anything that I can do to fix this? I know this is a electronic transmission. Can I just have it reprogrammed?