The gasket kit is P5249320 and the bolt is P5007515. I got about half dozen gasket kits and 2 bolts....and the bolts are around $60 unless you go to Jegs, then its $81.99 :angry7:
Doug's Headers part # D450, a little pricey but a very nice looking piece.
http://www.dougsheaders.com/online_store/product_detail.cfm?id=130
Spitfire also makes one, but I heard people have been having problems getting them.