Ok, so I had another set of lug nuts fuse themselves to the GM lug bolts at the sub-molecular level. Results shown here. Stock nuts and original hub lug bolts this time.
This gave my a GM K2500 series an 8-bolt to 6-bolt conversion without the pesky hub adapter rings..
Two winters in the Maryland “road de-icer with new improved sulfuric acid additives” really did a number on these hubs. I “think” part of the issue is more adhesion in the wheel acorn seats due to the dissimilar metals in the aluminum alloy wheels and the mild steel lug nuts. They seem to have more stiction- even before the nuts corroded onto the studs.
So, anyone that wants to preach the “never ever put any thread treatment on wheel studs” gospel will need to preach pretty hard with me. It’s not a hard job to replace studs, but the hubs, rotors and calipers all need to come off. It’s just a pain in the neck.
On the other side of it? I discovered that a sufficiently low-power impact wrench will in fact not twist them off— but with enough Penetrating Oil and patience, can convince the stubborn nuts to dislodge from the acorn seat in the Eastern European alloy wheel. The remaining 6 all let go after a few minutes each of Harbor Freight Impact Tool gentle persuasion— after, of course, I got the truck back to the shop with better tools. One twist of the Breaker Bar and 22mm Heavy Duty socket had been enough to spin the broken studs on the first two— which fostered a serious “Oh, Krap” moment.
So, I’ll say the electric impact wrench made life a lot easier in the shop once again.
Your Mileage May Vary