speedometer, id start by pulling the cluster out, as this way you can check both tach and speedo, to check the speedo just spin the part that the cable is supposed to spin, if your needle moves, then move onto the cable, i think a replacement is around 20 bucks......as for the tach, first check your circuits on the back for any broken ones, it seems to be common lately, if everything is good there just follow the wire back to the distributor, if theres any breaks or places that its not making a connection, even on the distributor cap then just connect it back, or replace it.... but its looking really good