Speedo recalibration

[Faithallen2003]

Recently put 35-12.5 on my 91 blazer believe it has 3.73 gears and is all stock need help figuring out what tooth count will correct speedo. Thanks for the info anybody.

 

[dhcomp]

91 has an electric speedo. Buy one of these from this guy:
http://coloradok5.com/forums/showthread.php?t=273863&highlight=drac

I just bought one, and he did a great job modifiying it. Similar ones go for $100 on ebay....

Then go here
http://www.tbichips.com/drac/

and set the dip switches properly.