3.73 gears installed - how will my speedometer react?

[vicj]

If you install taller gears (3.73)and your speedo was NOT re-calibrated) would that equate to the speedo reading higher than your actual MPH or would it read lower than your actual MPH?

I had the 3.73s installed some time ago and the dealer said that my speedo was recalibrated but I'm not so sure anymore!?

 

[dave6666]

Plug your numbers in here.

SS #670 with MM6 manual and GU6 3.42 gears

 

[Gus Strakes]

Your speedometer will read higher, and your odometer will turn faster. I drove a GTS several years ago with 373 and no re-calibration, and, if I remember correctly, the speedometer was reading ~85mph and I was actually doing about ~60-65.

 

[plumcrazy]

same size tires (outside diameter) the speed will register higher.

 

[vicj]

DAMN... I knew that my improved 0-60 times where too good to be true!! I'd better get calibrated!!!!

BTW, what will it take to re-calibrate?

 

[Whoaa GTS]

Speedo re calibration box. Has a bunch of dip switches inside and you just flip a couple of them depending on your gears 3.55 , 3.73 etc.

 

[FATHERFORD]

Speedo re calibration box. Has a bunch of dip switches inside and you just flip a couple of them depending on your gears 3.55 , 3.73 etc.

What does that look like? Does it require a power wire?

I bet that's probally what that damn red wire is for on my viper.