There’s countless longtime XF forum members who have been on here for years that are in line waiting for a used NW DCAI along with other performance and rare parts. Headers maybe but I doubt it as well. I’m not trying to be negative but this happens quite often with new members. Rarely do these come up for sale and if they do they’re more than likely sold in private between members. I’m just saving you some time so you’re not waiting around. Personally I would buy a new set seeing as you’re more than likely not going to get a used set for any cheaper than what you would pay for them on Black Friday. Cheers and welcome to the forum. 🤙🏼