JDM Speedo to Read MPH not KMH

speedo, wondering, read, options, zeroyon.com, change, custom, http://www.zeroyon.com/index/content/view/20/47, version, usdm, work, ratio, swap, faces, 100kmh, converted, fine, tuning, 240sx, speedometer, 180mph, gear

Have a JDM Speedo, I want it to read MPH not KMH, all I know is 100kmh is about 60 I was wondering if anyone converted one like this 180mph speedometer for S13 240sx (using JDM speedo) or fine tuning for gear ratio change - zeroyon.com My other options will be custom faces but I wondering if I can just swap in the USDM version and it