My 1925 pickup came with an uninstalled speedometer.
Does anyone out there have a picture of the dash with the installation holes in it minus the speedometer?
I would hate to mess up my dash!
From the clubs book; SPEEDOMETERS, By Russ Furstnow
Your dash board has a slight curve to it near the right hand side. That is where the plate should be to look correct. So, that 3 1/4" measurement would probably be it.