Supposedly your OEM 1987 plug wires' resistance are matched to OEM Bosch spark plugs. The Platinum plugs have a different resistance. Bosch has a chart that says these plugs will fit and have similar heat range but the resistance isn't the same. I am not sure what the danger is, but it is known that the insulator on Platinums can crack. However, I do use Platinums in my 1984 Rabbit race car with absolutely no problems.