FWIW, I had a brand new set of TTI W2 headers where the drivers side just did NOT fit. I'm talking with engine on stand, not in the car. I called TTI and discussed with the owner Sam, he indicated the headers are made on a jig and could not be wrong. He did however agree that it was strange they were touching both the head, and oil pan. He was kind enough to send me a second drivers side header at his expense, to Canada on my word. The new header fit perfectly. Moral of the story, anything can be made incorrectly, and TTI went over and above on their customer service. How it was made incorrectly still remains a mystery.