Check out this thread. Valve employee confirms that back shells are compatible, but front shells are not.

I’d still take it with a grain of salt though and wait until I start seeing other people do it.

Black Mesa takes a few creative liberties, and very much feels like its own experience. I’d call it more of a remaining than a remake.

Personally, I think the original is much tighter in its level design and pacing. Black mesa changed a lot of the levels and puzzles, sometimes for the better but not always.

I remember when I got my index, it was just waiting for me on the porch as I got home from school.

Alan Wake 1, I think. Got it for free forever ago, so might as well catch up for AW2.