Well, I don't know what the one I bought was for...just bought it and put it on.
The following information is on the white sticker in the photo in my previous post. Serial# 103367-B Type:B Date of MFG: WI 803.
There is a toll free tech support: 18005514955.

I don't know if the yellowbox would work but you might call them and see.

If you are on a budget, you might try the Cyberdyne 9901 Speedometer Calibration Box
at less than $50 from SUMMIT RACING.I haven't tried it but it sounds like it would work.
Keep us informed on what you do.
Everet <img src="/forums/images/graemlins/patriot.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />