I have the FS street header on my car. After a year and a half of commuting and the occasional spirited drive with other 5280 members, it has developed a crack where the collectors meet and head into the cat. FS offers a one year warranty on their products, so I couldn't get it replaced under warranty. However, Randy was more than willing to make me a deal on a race header/flex combo if I wanted it. After doing a little research, though, I decided against it.
Now, as for Ford Racing, I spoke via e-mail with Ray Dixon at my Ford Performance; he says that the Fr rep he talked to said that they will replace or repair an itme that comes straight out of the box damaged, but once the part is installed, there are no repplacements/repairs/warranties, etc.
I think my next header will be a JBA. They offer a lifetime replacement guarantee if something happens to their part.