Absolutely, I took it to an exhaust center and they installed the headers, and at the time I just didn't know about the car enough to look for problems. The flanges were not milled flat and they knew it. Rather than suggest that being done they installed them and got two more trips to their shop for "tightening" the bolts. I even bought APR locking bolts and they even ended up torqued too hard and broke off one of, which in turn cost me a new tap to re-thread the bolt hole. More $'s for them. Hurt but once I be-friended a ford tech who pretty much owns his own dealership, I got it right with the BBK longtubes. Sucks when you get raped for little of nothing that turn into alot.