If the vehicle is past a certain age, the odometer reading no longer matters for legal purposes, and as far as tampering, if it's been duly and legally noted on the title that the speedometer/odometer has been repaired/replaced and that the displayed mileage is not correct, it also no longer matters legally.
Hell, I've got a '92 Grand Am with over 342K on the odometer - I take it as a matter of perverse pride.
