I would get the ceramic coated up pipes from BWD they will seal up better than the stock up pipes. I have had trouble with the the exhaust manifolds working loose, now I have a broken bolt on the #8 rear side. I tried drilling it with a left hand bit no luck yet. I plan to pull both mainfolds and install B-7 allthread studs so I can get more pressure on them, and maybe some safety wire to keep them tight.