Review on Dorman 674-659 Exhaust Manifold with Integrated Catalytic Converter: Non-CARB Compliant | Best Deals by Tim Toscano

Installed this on a 2004 Nissan Sentra SER Spec-V during a headgasket change to prevent additional damage from a factory ancestor which is getting worse could. As others have described, the hole pattern in standard heat shields is slightly different than the bolt holes on the header. I found that I didn't have to drill holes to line up the placement, instead I flipped the heat shields over and hammered the back of the shields to round out the factory stamped grooves. Just a little, but all it took was a hammer and they fell into place. I hope the heat shields last longer with a hammer and don't rust compared to cutting and drilling others. Knowing I needed to make changes I didn't put a star, the conclusion was due to a aging engine on the manifold gasket that was sent. The one I got in my AJUSA kit was an MLS gasket which was a better quality than the one that came with the header kit.