It's called "experience", Mr. (no name) hobbyshoper. You may criticize when/after you have some.
"Crossover", "H-pipe", "X-pipe" or Y & Z are of NO VALUE on an inline engine using headers because, they defeat the purpose as stated.
They are rarely used on Race Tracks/Drag Strips. In 'commercial service' they don't work either, due to maintaince issues.
The single exhaust pipe/muffler comes stock from GM. Running headers into one pipe is even more absurd.
You are simply a victim of believing your own "technobabble".
