You said one part, the supercharger install was multiple parts. The pulley swap on the other hand was literally one part. I know it isn't exactly the same but there are examples of one part that can do that. I understand what the headers can do low end as far as some losses. However, most (not all) people doing mods for power are mostly concerned with power in the mid to high range (and us people who only go fast in a straight line it is exclusively top end as we are below that for maybe a fraction of a second).
