Occasionally bits & pieces from Summit (the SST bend that became the Valiant's exhaust tip for example), earlier systems were sourced from SPD Exhaust, last set of bends & Marmon joints came from Columbia River Mandrel Bends. There's another vendor, whose name is currently escaping me, that I plan to use for the Sched 10 weld elbows to build an exhaust manifold for the Valiant. I *think* they're marked at home. If they are, I'll edit this post.