What cars came stock with the LS 376/525?

http://ift.tt/2t3rKWX can't find any information on the wiki about it, but I've seen a few GTO's and Corvette's with this engine swapped in. Did this engine ever make it into production cars, or is it just a crate that GM sells? via /r/cars http://ift.tt/2txW0Nj