2 stories. 1. the machine shop i go to the guy is VERY negative and is picky about what motors he likes, he said he likes the 6.9 alot, the 7.3 he said usually needs boring and sleeving when rebuilt, so that was very pleasing to hear!
2. we had a mid '90s chebby dually 6.5 knocker come in when i worked at the dealer that was knocking louder than usual, the motor was worn out bad, someone used soda cans to shim the bearings up.....
we had it rebuilt, 6 months later it was towed in, the crank snapped.
GM quality right there.
-Jon