OK Lets start off with a list
2003 F150 Reg Cab SB 4.2 V6 5 speed
Tires Are Savero GT pluss 255/70R/16s
Tires are balenced rotors turned New Pads
My truck will seem like i have oval tires between 44-50 after that its smooth until 60-80 it will vibrate really bad my shifter will be going crazy. I have no idea whats wrong can anybody help??

 

A shifter going going crazy normally means an engine mount or transmission mount has broken. Have you had them checked out?

FX4-Texas