Help Identifying Headers

[JeffWeb]

Need some help identifying these headers on a new-to-me 1975 911 S. It's a California emissions car and original 2.7 engine but none of the emissions except what is probably the original muffler with a plugged EGR bung. I've searched and can't find a matching pic. Thanks Pelicans.

[77Targa0912]

Those are thermal reactor bypass pipes. They don't add much performance at all just reduce the heat problems associated with the log manifold.

[JeffWeb]

I see now, thermal reactor replacements made by Bursch and sold by our host. Thanks.