My truck originally came with 255/65/16 and i'm running 265/70/16 now, because of that my speedometer reads 3 over (when the speedo shows 60 i'm actually going 57). How do you adjust that? I've heard that it's something that bolts into the tranny and i've heard it can be adjusted with a programmer.

 

With that small of tire increase it shouldn't be off that much. Mine is only off by like 1 mph

 

I'm sorry, i got the sizes wrong

It came with 235/something/16 and i am running 255/65/16 now

 

That's still not much change. But a programmer can do it. They actually make one just for calibrating the speedo if you didn't want to program your truck

 

To be honest, this just gives me an excuse to buy a programmer

 

I hear ya buddy. Get ya a gryphon or sct. Go all out

 

Will a programmer allow for me to compensate for new 410 gears instead of my old 355s as well as tire sizes and which ones would be the best