'78 K5 Speedo Adjustment Gear??

[AZOffroad]

With 35" tires on the K5, my speedo does not reflect the correct speed. As was the case with my CJ-7, I expected to just have to swap out a $15 gear and it would be a done deal. The local speedo shop is telling me it requires something else (I think the called it a "ratio adapter"???) and it's fairly expensive (like $160).

My setup is 100% stock other than a 4" lift and 35" tires.

Are these guys full of it, or is it really that expensive to make my speedo read accurately again?

Thanks!

Steve
Gilbert, Arizona
1978 K5 400ci/TH350/NP203 Daily Driver

 

[4X4HIGH]

When i've done a gear swap or tire size change i just took my truck to the speedo shop and about $100.00 later i drive out reading accurately. There is an adapter box made by stewart warner i believe that does get costly if it is needed for the correction. If that is the case go to your local wrecking yard and look at some tranny's and pull one off, just make sure that it is a bolt together type and not riveted. There are 4 gears inside the reduction box and the speedo shop must be able to take the 2 halves apart and swap gears to make your speedo correct.