ok, after about 15 minutes looking through the searches, I give up.
I want to convert my 85mph speedo to the 140,(already have the white face overlays) and i read in a thread a while ago that you can send your cluster to 50resto and they will calibrate it for you. I cant even find it on their website
what year is your car? if its an 87/88 you will need an 89 cluster that is factory 140. i traded mine about a month ago. but found it on corral for 40 shipped put my working tach in it and my good plastic, used it for a month. then traded it when i put autometers in my cluster.