Have been trying to figure out how to get the right tire size figured out forever and everything I've tried doesn't seem to be working unless I'm missing something. Truck is a 98 k1500, every time i go into the tire/gear wizard its setup as followed tire tire: .74 with gears: 37.3 if i punch in the correct size 34.6 it wants to multiple by 46. Speedo is out about 10 on highway and 5 in town i should mention, any help would be appreciated