So I got my busted header stud out today. The guy damaged the manifold threads drilling it out, so he just used a 5/8" bolt to hold it in. Unfortunately, it's still leaking - not nearly as bad, but still leaking. The studs are shoulder-less, so I know that isn't the problem, and it's cranked down as tight as possible. The guy said the flange might have to be re-worked to fit? Would the extension that MAC sells w/ the prochamber work to seal this leak? Would MAC sell this by itself (bought the PC used and didn't get this part), or do I need to find a muffler shop that would fabricate something? I just don't want to drop another $100 and a day at the shop if I can just put the flange in and tighten everything up myself? Any ideas? Thanks.