If you like your legs connected to your body, I wouldn't get an original cast iron bellhousing. Get a new blowproof bellhousing from George Anderson at Gessford Machine. The bellhousing probably needs to be notched for the passenger side frame rail, and George knows what needs to be done to it so it fits correctly. He's very reasonably priced as well, as I don't think you'll do much better,. I think he's a new Shelby dealer as well, so he should know. He'll set you up with a clutch as well.
www.gessford.com