Hello, I am re-installing my exhaust that I had to take off my 2001 Blazer. I am having a lot of exhaust leaks where the exhaust headers and the exhaust pipe meet. It has a flange and what looks to me like a big spacer that goes between them. I am guessing that this is the gasket that they use. Do I have to buy new ones or am I just not tightening the flange enough.