im wondering because ive gotten my second slip on from an unknown company and again its doens't bolt up and fit perfect. the first time i had recieved a 450 pipe in stead of a 400 and the mounting brackets were off. ive now recieved my 2nd pipe and a tag on it said 426. the brackets will work but when i tighten the lower one above my brake it ends up tweaking the header out a little, and where the header connects to the pipe, its not a tight fit. the pipe only goes over the heard about and inch rather then 2 inches, this allows the exhaust to leak out from there. ive now waited about 3 weeks to a month for this pipe and if i get a 3rd one sent out for my 400 will be different then the 426 and bolt up. im almost ready to ask for a refund because of this bs. its just ive heard alot of good stuff about this pipe on here and i want one.