Speedometer Calibrator 12 Oclocklabs.
 

About 2 years ago I changed my rear end gear set from 2.47 to 2.82. I have been reluctant to re-calibrate my speedometer as I wasn't sure if I would keep the 2.82 gear set and the fact that the local speedometer shop wanted $250 to re calibrate speedo.

So I have seen many re calibrators but all were fairly expensive and some were rather large. But I recently came across this very simple and very tiny one for $90.00 delivered.

I hooked it up and it work's great.

I will add that my speedo is using a 3 wire hall effect sensor instead of the original 2 wire passive VRS sensor. So I would ask them about that before purchasing. But so far I am very happy with it.

They are a motorcycle oriented company and sell the unit as plug and play for most bikes but the universal kit is what you use for cars and trucks.

http://shop.12oclocklabs.com/index.php?route=product/product&product_id=59

So I got in touch with 12 Oclock labs today. They do have an add on converter for the VRS type passive sensors used in most 80's Mercedes. They don't have a picture of it but he did say it was about the same size as the universal U1 kit, which is tiny. So you order the U1 kit and the SDRD_U2_ADPT adapter. for ~$110 + shipping. Also he said they haven't really tested this on to many vehicles but to give them a call if it doesn't work. Seems that are willing to work with people. Sounds pretty good if your space constrained but I would go with the Dakota Digital or Yellow Box system or similar if you can find a good mounting location.