They look like the Ebay M2 headers. I don't think that mine cracked,through they may have, but they developed a leak somehow that caused me all sorts of headaches( idle surge, stalling, bouncing rpm). Replaced the gasket with no luck. I actually bought a second set. Before I installed them I put a straight edge to the flanges. They were so far off I threw them in the trash. Didn't even bother with trying return them. Also the EGR tube was nearly welded shut.
I bought a set of gibson and the quality difference was night and day. They sound different not better or worst, but they eliminated all the problems the m2's were causing. However I've read plenty of people who have used these headers with success. I guess quality control is hit or miss with these types of units.