There are two (2) different VSS's for all manual trans;
1984 SENSOR, vehicle speed 25007336 $44.15 1985-88 SENSOR, vehicle speed 25036929 $53.75
Trans gearing is not a factor in speedo gear selection, just tire diameter as the speedo measures axle RPM. 215/60R15 tires use the same speedo gears as 195/70R14 tires. These tires (195/70R14) do have a listing in 1984. If you use a 14047637 (35 teeth, color code natural) drive gear and a 10041031 (29 teeth, color code red) driven gear you should be all set.
From: Scott Backer