Don't know who knows about it but vehd.com is a great site for all horror fans from exploitation through to oldies. I've found some great stuff on here, and not just horror, they aslo have some great film noirs, as well as every other kind of movie, including most new ones. Here's a link
http://veehd.com/search?tag=gore&page=4
I know it's a sign up job, but don't worry they donn't bombard you with crap and there are no hidden fees or sudden 'premium rates' or all the usual junk that most download sites have. Give it a try and let me know what you think of it