It is an OEM replacement, not an upgrade. Better performance? No and there is little resistance and actually they are very prone to cracking, even the version 2 manifold. The stock manifold is fine if you have solid motor mounts and better if you have an exhaust with a flex section. The only reason the stock manifolds crack is because the j pipe is bolted to the engine and stock motor mounts give way too much play in the engine bay. So excessive engine movement and no flex section causes a lot of stress. So the added stress has to go somewhere and it ends up at the manifold