4-1 high end 4-2-1 low end

usually 4-1 for built engines, 4-2-1 for not so much engine work.

this is very general, you can get custom headers made to work at certain rpm ranges based on the length and angle of the runners, but im not going to get into that now

 

well said..... usually most street cars only need the 4-2-1 header.

 

Ah good to know, thanks!

I am not looking for loudness and I really dont plan to do much engine work. My old stock exhaust is rotten and is gonna fail inspection and I just wanna buy the right stuff once and not regret/make changes later...