step

Nice read. I'd say, yep, your right. Even small low output engines could have a custom header designed for them that would out perform OOTB on the shelf headers.
Pricey though, a bit outta reach for me. I'd like to read more on the subject.
a bit more reading
http://www.perfweldheaders.com/headertech.html
Mark, the owner of Performance Welding Racing Headers is a member here.