can someone explain this?

[blindsnyper]

is this a stock header and not a manifold?

[CodeRed]

It's a manifold.

[Ever Victorious]

My vote is for something halfway between. It collects exhaust gases into individual pipes like a manifold, but the mounting flange doesn't look as smooth as on headers.

[weems84]

I thought exhaust manifold or exhaust headers were the same thing with two different names. I looked on wiki and it said...

"An exhaust manifold or header collects the exhaust gases from multiple cylinders into one pipe."

link: http://en.wikipedia.org/wiki/Exhaust_manifold

[blindsnyper]

a manifold is usually cast, like this...

and a header is made with tubung, like this...