Yea, sure, I see your point.

On the other hand, one has no way of knowing how it is going from inside. Following your logic, we should replace all the pipes with the hoses from auto zone on a new vehicle

 

Are you insane? Replace everything on a new car? His car by the look of the pic has "some" miles on it. The oxidation on the throttle body,. the rust on the trim ring for the intake tube. Even if it only had a few thousand miles, he must live in a climate where corosion is bad. He asked about a part, and given all the factors he should replace it. Now mabey yes, he should start going through and replacing as many things as he can. But only the things that "will" break down and finally just break.

 

Sure I'm insane if I dare to disagree with you

To me outside corrosion on the pipe is not an indication of inside corrosion. More, I believe there is no visible indication to inside corrosion whatsoever. My 92' has much worse corrosion there, and I will just leave it until it breaks, and then will deal with that.

In my previous post I just tried to show you where your logic leads - since one has no way of knowing how bad inside corrosion is, one is better off replacing all parts prone to corrosion with non-corroding ones...

However, I do believe that those pipes ( and everything in the car for that matter) are designed the way they are for a reason, even if I don't know what this reason is, and I don't want to change the design unless I absolutely have to...