I have been told Langdon Stovebolt Company and Patrick's Antique Cars are fierce competitors. I was ordering some Fenton headers along with a new carb and other items from Langdon. The headers arrived, still in the Patrick's box.
And after ordering a rear suspension kit from TCI, I'm guessing that Chevy Duty and CPP order their kits from them. The kit I received was identical to that shown in the CPP catalog, not the TCI catalog, but that's a totally different story.