I'm in the process of trying to get the 15 year old exhaust housing off my old stock turbo. I'm fighting a losing battle here. It's been soaking in WD-40 for days and still nothing. Any secrets/tips would be greatly appreciated.
I recall speaking to John Craig about this. He said something like, "We just break 'em off". I said, "Good, I'll send you the turbo, and let YOU break 'em."
I don't think it'll help, but you might try PB Blaster. WD is child's play compared to PB. Follow the directions on the can, including tapping on the fasteners after you spray 'em.