[dgax65]

I hate to say it, but no kayak handle is going to stand up to 3000lbs. Regardless of the breaking strength of the strap, it is only attached to a piece of relatively soft plastic. The hull material will fail well before the strap breaks in most cases.
How did it fail? Did the strap pull out of the plastic, did the stitching fail, or did the strap material tear? It is possible that you just got a bad strap.