it comes up with 2 Bosch parts: NA 13 X and NA 12 X. Does anyone know the difference between these and which I should put into my '82 Rabbit (1.6 NA)? NA10X 77 - 80, 1.5 engine NA11X 83 - 85 TD NA12X 85 only, ME 1.6 NA NA13X 81 -84, NA NA14X 86 to 91 NA NA15X 1/91 - 92 TD (eco) Loren