No, I know a source that will make a converter box that is spliced into the speedometer cable. Essentially you send them your speedometer cable marked where you want the box to be, it’s smaller than a pack of playing cards. I marked my cable so that the box sits on the top of the transmission. You tell them what ratio you have. I told them I was moving from a 3.54 diff to a 3.058 and they set up the gearing in the box so that the speedometer read as if there was still a 3.54 diff back there. They make up the converter box and put new fittings where they cut you cable so you wind up with two short cables with the box in the middle. I’ve had it installed about 5 years and it works perfectly and it’s as accurate as it was before the diff swap.