A bunch of bogus Cavs, Spurs, Warriors and Bulls championship rings have been seized in a recent customs bust at LAX ... and officials say the crooks could have moved the pieces for around $560k!!!

U.S. Customs and Border Protection officials say they intercepted a wooden box full of 28 title rings that was heading from China with a final destination in Arizona. Officials believe the fake rings were going to be sold as a collection.

The rings look pretty cool, but when compared to the real thing -- you can tell they're duds.