Worry about performance first. Sound good s second and will take care of itself. Sound comes from a few various sources. The header is really not one of them. The header will deliver a few more db’s them iron manifolds.
Largely the rhythm of the sound is from the cam.
A tight, drum like sound comes a lot from compression as well as the cam lives actions. Compression has a lot to do with it, cam action second.
The last is a biggie! Not only the size of the exhaust pipe plays a roll, which is like the size of the loud speaker diameter, but the actual muffler used has a major roll.
Custom building your own headers is a mountain of work to tackle. The main thing is to do the math on tube length before you do anything at all. This is dependent on the engines build parameters and parts used to obtain the goal your after.
Then! Then comes pipe routing plans, then Cutting!
I look forward to your project postings and pictures.
Welcome aboard!
