I don't think there is a way to tell exactly which car it came from. You can figure out the year and gear ratio. The only way I've identified them was by the grooves on the input shaft:
0 Grooves - 1st/2.85, 2nd/2.02, 3rd/1.35, 4th/1.00
1 Groove - 1st/2.54, 2nd/1.80, 3rd/1.30, 4th/1.00
2 Grooves - 1st/3.11, 2nd/2.20, 3rd/1.47, 4th/1.00
3 Grooves - 1st/3.50, 2nd/2.48, 3rd/1.66, 4th/1.00
