This past January I installed edelbrock coated st st headers on my truck and here's what I found:
- Header bolts haven't come loose yet
- Header bolt heads don't match; some are 12 point, some six point.
- None of the bolts or washers are stainless steel
- One pipe was damaged in the box: obviously not their fault, but it could have been avoided with some sort of packaging. Yes even these expensive headers had no packaging to speak of
- O2 sensor bung couldn't be in a worse location: if you're using a factory 'long' O2 sensor (as opposed to some aftermarket O2 sensors which are short) there is almost no room between the top of the sensor and the heat shield at the firewall. So unless you install some type of protector around the wire(s), they'll be worn off in no time.
- They don't tell you that the O2 bung is so far away from the head that you need to use a three or four wire O2 sensor, cause the one wire O2 may not be hot enough at idle to pass a smog test.
- One of the clamps that connects the y pipe to the headers wasn't coated
- None of the supplied exhaust pipe clamps are stainless steel, or if they are they're pretty cheap, because they're all rusting
- Adapter pipes that go from the collector to the cat are made of some really cheap steel, as they look like they're ready to rust right through at any moment, and that's in only six months. I even undercoated them before they were used. I find even undercoating the exhaust seems to keep the rust down from the outside; even if the oil burns off, there seems to be some kind of chemical residue which protects all but the cheapest of materials. If st st was too espensive, they could at least have supplied aluminized steel pipe as is used at any joe blow muffler shop
- Either the coating is burning off, or the headers themselves are starting to rust; cheap grades of stainless steel will rust
In summary, I was quite disappointed with the quality vs cost of the edelbrock headers. I would have expected this mess with some cheap hedman headers, and you know what, I wouldn't have even been upset because at that price I would have expected some issues. At the time I was thinking about buying the Gibson headers, and in retrospect I'm thinking I should have.