swapped out 3:55 gear to a 4:10 gear now speedometer is reading a faster speed.

[djtruzy]

swapped out 3:55 gear to a 4:10 gear now speedometer is reading 10 mph faster.
Need info on how to correct speedometer reading error.

[03Merc]

You need a hand held tuner.


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[loud2004marquis]

^^^What he said^^^

[Ambitious1]

Reach out to Marty from mosspeedshop.com for a tune. He is a member here. A tune will correct the speedometer issue and will make the shift points a lot better. You will be very happy you did.

[RubberCtyRauder]

You need a SCT xcal 3 or 4 and a tune..see Marty O as mentioned. He can set you up with all

[Spectragod]

Or, with a pass through device and a editor, you can edit the as built in the byte map and adjust from there, just 1’s and 0’s...


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[justbob]

Meh. These will correct it.

https://uploads.tapatalk-cdn.com/20190910/781a5a1996f60ac85e50e664558f00 d2.jpg


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