Gt380 restrictor in middle header pipe

[stingy1]

The manifold that serves middle cylinder, I bought a nice new looking one . It had a press fit restrictor in it reducing the size to about 50 percent. It won't come out , will have to grind it if reduces power. Just wondered if it was fitted to a certain model gt380 or market? Tried heating etc it won't budge.its fitted at the point where header bolts to cyl head

 

[stingy1]

Will add , it came from Germany. Old stock used but great condition