I have been a GM trained Cadillac Tech since 2003. 6 years of that I was at a standalone Caddy dealer.
I have misspoken here. The OE bolts are not Torque to Yeild. I have posted this on the forum many times since 2007. OE Northstar bolts are reusable per GM's documents, but you need to clean the bolts, reapply the threadlocker, and apply sealer to the washer to keep fluid out of the bolt holes.
I have use the GM big serts 1 time and I have to plans on ever doing that again. I have used the NS300L inserts and feel they are the best choice.