Hi all. I have a 86 GT with an AOD. Ever since I got the car, the speedo has been off. From around 0-35 mph it is about 5 mph ahead. From around 35-55 mph it is about 10 mph ahead. From around 55-80 mph it is about 15, and so on. Could this be because of a different gear ratio? I don’t know what a regular gear ratio would feel like but I can say I am running around 2.3k rpm at 70 mph. How can I fix this?