On my 73 Electra 455, are the flanges on the exhaust manifold part of the exhaust manifold and not removable? Or are they removable and just been on so long that they look like they are a machined part of the manifold?
Sorry, I am not sure what you may be asking, but to help clear things,
If you to: 455 casting numbers, HERE ,
scroll down the exhaust manifolds, you will find some of them link to pictures.