JA2 brake system?

Have you tried looking at the RPO code sticker in the trunk?

Actually no. Is that where such information is located?? I tell ya, learn something new everyday.

Since around the mid 80s, either on the underside of the trunk lid, on he spare tire cover, inside the spare tire cover on wagons, inside the glove box on trucks. White label, black lettering, lists every Regular Production Option the vehicle was built with.

Glad to help (if it helps).