Then you are barking up the wrong tree. These cars are always requiring some sort of fix.
1984's have issues with brittle wiring in the engine bay area.
84-85's have the .60/.63 A/R turbo. 85.5 and 86 had the .60/.48 A/R turbo
1985.5 and 86 have the flush headlights and PE EEC processor for a bit more HP. They also went to a single in-tank fuel pump, dual exhaust, and have the H2O cooled turbo.
1986 models received a 3rd brake light