Header tether needed?

[Sean Cour]

Originally Posted by bykr

After doing a search on here and not really finding a definite answer I'm wondering if I need a tether on a collector extension that has a three bolted flange. The Collector is welded to all four header tubes(street style header).

So lemme get this strasight......you’re on the forum, telling everyone how knowledgeable you are in manifold/head engineering, but can’t figure out the header tether rule?