Were the extension pipes 2.5-3 inches too short to mate up with the 3inch cat back system? If so, that is the same as OBX. I thought it was small issue, but some might not like that. I purchased dynomax clamps as I thought the clamps were junk as well. Even the Corsa clamps are junk, in which...
Quite honestly, the market is pretty flooded with header mfg's for this platform. They cover the price ranges from $450.00-2000.00. I'd say there is a mfg for everyone's budget.
These are OBX headers. The only issue was that I needed to add 2.5 inches of stainless to each midpipe to connect up to my Corsa Sport. The O2's are tilted for e85. I have yet to take out an O2 running E85 for 5k miles. No issues with the installation. A small ding may be needed for the steering...