Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
I will look tomorrow at the Service Parts ID label on the truck's glovebox door to determine if I have JN3 brakes.No date codes on calipers that I know of.
Does it matter that they're original? If they were, I'd bet that they're full of crap, and the pistons are half-seized. If so, the sooner they come apart for cleaning, or get replaced, the better.
If you have JN3 brakes, you need to upgrade both the front and the rear, along with the master cylinder and booster.
I'd say it's highly unlikely unless the truck is a super low mile creme puff.