71 Dodge Dart Swinger in England

I have a set of Doug's headers that have the same raised area, according to them, that is by design. I don't plan on grinding mine down smooth, I'm installing them as is.

It will change the header location slightly if those raised area are removed.

Headers have always been problematic regarding keeping them from leaking. Something you need to stay on top of. That's why some people would rather have stock exhaust. On a Chevy it's not much of s gain to put headers on, on my Dodge 318 it is big gain, worth it.