Since I am running 285's on my truck my speedo is off. i know about the superlift box but I'd rather not splice wires. Can a good scanner that streams live data change this or do i need to go to the stealer?

 

Only way to change the speedo on the older 12v trucks is to switch out the gear in the transmission that I know of.With 285's the speedo is not off all that much unless you a stickler for detail I'd just drive it.........Andy

 

Should be out ~7% with 285's

 

There is no speedo gear. That would be easy if it was. Mine gets the speedo reading off the VSS on the rear diff. I would like it fixed because the VSS sends signals to the PCM for trans shifting.