I can confirm 89-91 squares for 30 spline. I just went thru this .Of course there may be other years .Mine is an 89 blazer. 10 bolt ,8.5. I have an auburn locker that a want to keep , same as you .
It's cheaper to get a dropout somewhere else. LKQ doesn't include accessories, harness, ecm etc. And you don't have to pull it. I'm not poo pooing, just trying to help