Yep, the famous ill designed and often poorly constructed with no QC check almost never being made, the old 1 size fits all basic street header.
The glass packs can vary ever so slightly on the inside. There lengths can change. For the most part, there good for fishing weights.
A good muffler will make more and useable power over glass packs.
The headers are fine minus the scraped and flattened pipes, which all ways happen with this style header.
Any header other than this design is expensive and worth it.
For a street bound A body car, look to Doug's or tti headers.