through my tires/gears change and some handy use of calculators i've basically changed my gearing from a 3.55 to a 3.81, i was wondering if anyone knew what speedo gear to go with and where i could find one? and also til then what kind of MPH i can expect to be off (at like 60mph for example)? thanks a lot for the help i'm sure i'll get

 

ford dealer should have it for about $5, outta be able to tell ya what color/tooth count to get.