The Heart is a Lonely Hunter was more or less required reading in High School English class back in my day. At one. If there's an influence, it's probably more in their philosophical approach to how their subject matter is presented. There's a certain I know it's pointless but damn it, I'm going to do it right anyway behind their writing that I find at least somewhat similar. I feel like Buk's writing style changed to a greater degree over time than did McCuller's, at least in his poems, which started out with longer phrases and more abstract imagery and eventually became a much more terse style probably most evident in You Get so Lonely...in 1986.
McCullers often wrote in shorter sentences, so stylistically, any similarities are most likely found in their novels. Despite the relatively terse sentences, I'd say Buk's writing was far more graphically blunt than was McCuller's, but she was fairly blunt in a more delicate way, if that makes any sense. If anything, I think Buk probably related to her as something of an outsider and a writer who didn't rely on any tricks; she just basically put it on the page.
