Some people say that the idea behind headers is to line up the exhaust pulses
one behind the other in such a way that the pulses "pull" the exhaust out the pipe.

That's why most headers will merge four non-competing pulses into two non-competing
pulses that will merge into one pipe so that all four exhaust pulses are traveling down the
pipe on the way to the exit.

Some people say there is a formula related to engine displacement volume per cylinder
and pipe size for each cylinder.............as well as the pipe size for when two cylinders merge their
exhaust pulses behind each other. There is also a certain distance between each merging
point so that exhaust pulses don't "hit" competing pulses and slow down the flow. With cast iron
stock headers, the exhaust pulses bang into each other and that's why racers
put headers on their car.

A car engine is a wind-machine and the faster air goes through the engine, the faster
the engine runs......more horsepower.......so to speak.

The people who say that headers should have "back pressure" going back up the
pipe are usually making excuses for poorly flowing headers.

If a person is making headers for "show" instead of function, I guess all they
have to do is make them look nice.

If I have it right about the engine your headers are going onto, it looks like the exit
is going out the side of the car. Did I get that right?-Bob