Before this thread gets locked for something of illegal usage, its my personal vehicle and its not for sale...EVER!!...(Yes EVER!)

In my quest to add parts to my car I had sent out an old cluster I had to AutoInstruments to restore for my 69 Charger. I forgot to tell them to zero out the odometer and they restored my cluster beautifully but the ODO shows 66000 miles. My existing cluster shows 8430 which is a true number since thats the miles she has gone since her full restoration.

How do I get the 66000....to read 08430? I know I can put it on a drill press with a rubber hose and sit there for hours on end til it reaches 08430 but I do not want to wear out the bearings on a fresh Speedo. I know I can open the speedo but there is a mess of little gears and it looks a bit confusing.

What do you suggest?