Gentlemen:
We are trying to help someone asking questions, lets not get off the subject and
take on personal licks.
Any muffler will work as good as another, new or used.
I have to disagree with John H, all mufflers are not
created equal. Whether you choose a bullet style, pancake, louvered, glasspack
or chambered, they each have their own exhaust tone and some move air better
than others.
Please re-read the two statements.
John's statement did not say created equal, but will work as well.
Inline--yes, each has their own tone and air movement.
On a non-race engine on the street, I do not think it will make that much difference in which you choose.
It depends on the sound you want if sound makes a difference to you.
For most Inliners, I think the sound is it, otherwise we would probably use V-thingie for ease of use and parts available. I did not say ALL.
Running headers into one pipe depends on the size of single pipe.
Suggest re-read postings with an open thought to see how they sound to someone asking the question.