Technical fenton 6cyl chevy headers

So, ive tried to fit my fourth, 4TH SET of the new ting-tang fenton **** headers on mine and customers trucks.
First off- theres about a 3-4 lb difference in weight between the real ones and the jippo china ones.
Next comes the machining issues to mate them to the head. They have to be machined flat to fit the head properly.
I could go on about the thin walls, but I hope you get my point.
Theres still plenty of orig. ones out there,

 

Who's making the jippo china pieces? I bought a spare set (nearly new) a couple of years ago; which could be some of these.

 

China manufacturers have been known to "modify" specificatins now and then. Less material at the same price is one of their favorites.