I sent a standard Rev 3 turbo exhaust manifold gasket to the chap making my exhaust manifold so he could get the flange made up, he noticed that one of the ports on the gasket is larger than the other 3!!!

What is the reasoning behind this???

Does the standard manifold have one runner larger than the others???

Do aftermarket manifolds take this change in port size into account???

Can I ask any more questions in 1 post???

Ta

Jay