speedometer correction. what is needed??

[damage inc.]

my buddy just dropped his 98 gt off to get his 4.10s in. its a t 45 car. what all is needed to correct the speedometer?? i was led to believe just the little plastic gear in the transmission? is this correct??

 

[MachAzure]

You cannot get a speedometer gear with enough teeth to compensate for the 4.10 gear ratio on the t-45. THe highest possible speedo gear is a 23 tooth which compensates up to a 3.55 gear.

To get the speedo accurate- I would get the Dallas Mustang speed cal
http://www.dallasmustang.com/index.mvc?Session_ID=6a5140af0bbde7114b37f2b1c30dd1a3&p=9910

This way, he can correct for the gear change and any future tire diameter changes.

Plus, it is a very simple install- you only have to splice into one wire.

 

[Cobra Jay]

You cannot get a speedometer gear with enough teeth to compensate for the 4.10 gear ratio on the t-45. THe highest possible speedo gear is a 23 tooth which compensates up to a 3.55 gear.

To get the speedo accurate- I would get the Dallas Mustang speed cal
http://www.dallasmustang.com/index.mvc?Session_ID=6a5140af0bbde7114b37f2b1c30dd1a3&p=9910

This way, he can correct for the gear change and any future tire diameter changes.

Plus, it is a very simple install- you only have to splice into one wire.