headers and exhaust manifolds

Are those the same thing?

I guess based on what they do they are the same thing but headers are usually made of tube whereas manifolds are generally cast iron. Headers are usually designed to flow smoother than stock mainfolds thus increasing power

Manifolds tend to be quieter under the hood than headers.

Originally Posted by 67stang347

Are those the same thing?

Nope

AS stated above headers and exhaust manifolds are not the same but they do the same thing. Headers are used where performance is more important than noise or easy access to plugs and starter. Even factory "performance manifolds" or cast iron "headers" don't flow as well as a good set of headers. Headers can also be tuned to some extent by using a piece of tubing the same size as the collector to make your collector longer to match your cam. You can add some low end to the cam without hurting the high end. Reducers can also be made to limit the restriction and reduce the back pulse over the longest range of RPM.