Speed-Cal settings

[85MustGT]

I just got taller tires and my speedo is off.

Current Diameter = 27.8 inches
4.10 gears
1998 Mustang GT with a T45 tranny.

Does anyone know of a chart or a way to calibrate the setting?

 

[BooWFO]

If it's the dallas mustang one.
Clicky sorry it's on lefthand side under tech info.