cop car speedo
 

if i put a cop car speedometer in my fifth ave do i have to recalibrate it because it goes to 125 mph and mine only goes to 85. if so how do i do this?

i am almost positive you just hook it up and know how fast you are going. the pinion and cable will spin the same no matter what, the speedo translates the rest...

it should be fine i agree with john. the only time you should have to recalibrate the speedo is when you change rearend gears or tire size (height) and then thats just the speedo gear drive in the tranny.