One forum member sent me a picture. I have discovered that when I sent the speedometer in for resoration I had left that part on the back of the spedo. So I've called the company that restored the gage and they are looking for the part. If not found, I'll be searching for a replacement. i thought it might need to be calibrated with the speedometer or I would not have included the adapter when I shipped the gage. Just one more lesson I've learned restoring the Bigbolt!
Anyway, thanks for trying to find the part number.
