Look none of that is in the question!!!!!
Are you trying to prime an argument on this mans thread??? Your getting yourself ready for being embarrassed !!!!!
Lets say I'm running a street rod With an exposed engine? I would want a classy looking exhaust with a header ! That may be what the thread starter has in mind.
Wait till he comes back and you can warn him his engine is going to fly apart! And he built the wrong engine! And you can school him in the way he should have done it!!!!!
And post pics to show him what kind of exhausts you have built!