Bookworm, what a shame no-one has seen fit to reply to your post yet. McCarthy's most obvious stylistic ancestor is William Faulkner - if you haven't done so already try out 'Absalom, Absalom!', 'Light in August' or the lovely Modern Library edition of the Snopes Trilogy. Otherwise, you might want to look into Barry Hannah, Larry Brown, Lewis Nordan (a particular favourite of mine - see 'Wolf Whistle' and 'The Sharpshooter Blues') and the wonderfully twisted world of Harry Crews. Hope this helps.