Ford Ranger speedo off, I have checked with GPS and analyzer?

Ford Ranger speedo off, I have checked with GPS and analyzer? - 1

Added (1). I need an idea. The truck does not have a cable, this is an electronic speedo.
Thanks.

Added (2). Tires are correct size, analyzer says 66 truck speedo says 60 gps says 66
so I know speedo needs something?

Is the truck still wearing the same size tires it came with?

How much is it off - my F150 speedo is 3+ miles per hours faster than GPS speed at 60mph. I consider that close enough. The tires are stock and well worn so I suspect new tires will reduce the error somewhat. Most of my motorcycle (past and current) have been 10% + off - again speedo faster than gps.

Check tire size if the error is only slight.

The speedometer head must be bad.