86 would not be 4L60E or have VSS, so the wires would be the lockup converter ones yep, square plastic plug and two wires, i always forget which side of tranny the lockup wires are on, all 700r4 had lockup converter btw, some of them were white plug and others were blue
VSS started same year as when 4L60E replaced 700r4, this happened for 1992 model year for most but not all vehicle models