what brakes on 84 C-10

I need to find out what braking system is on my 84 chevy c-10 Scottsdale pickup truck. It originally came witha 6.2 liter diesel. I need to know If it's WITH JB1, JB3 BRAKE SYSTEM or WITH JB5, JD3, JD5 BRAKE SYSTEM.

I understand there is supposed to be a sticker under the hood or in the glove box. Neither of these stickers are there that I can see. I just see the emissions info and the VIN sticker. Neither say anything about brakes.

Can anyone tell me how to figure this out?

thanks!

Jason