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Drive Fast, Take Chances!!
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Discussion Starter #1
I know i have asked this question before but i keep getting different answers from everyone. i have a 86 GMC k1500 with a NP 208 transfer case

I changed my rearend from 3.08 to 3.73. now my speedometer is off obviously. I looked at a set that my buddy has for 3.73 and tried to order that set from my local Chevy dealer and the inner gear is discontinued. Can I make just the 21% change with the outer gear without the gears binding up? :confused:
 

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Don't know about the factory gears but you can go to your local speedo repair shop (most medium to large cities have them) and get a gear ratio add-on box. They will install a little black box in the speedo cable line with the exact conversion ratio you need and issue you a laminated speedo calibration certificate good at any Highway Patrol speeding violation stop. Cost used to be in the ~$50 range.
 
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