I started off by calling the local auto zone and seeing if their fancy hand helds could reprogram my gear ratio to try to get the Spedo close to accurate, but the said they don’t have anything that would go back that far (year model wise). They recommended some website that sells them, I think it was summit racing, so I called the local summit and they said they also don’t have anything that would go back that far. They recommended another place and same thing. So I called a local tuner shop to try to get the Spedo fixed (also a badass tune) and they told me they couldn’t tune anything older than a 1997. that’s when I found the cluster instrument repair shop in Atlanta, but I never pursued that. I was willing to buy a $500 hand held but could not find a single one that could tune mine guaranteed.