I just installed a 2 1/2" bassani x pipe to an otherwise stock 91 lx, and I'm having a hell of a time getting the x pipe to seal to the stock headers. I've loosened and moved and retightened and done just about everything I can think of and they still have a substantial leak between the headers and the mid pipe. I can't imagine that they only work with bassani headers?? All the surfaces were nice and clean when I installed the pipe. Anybody else been through this before? Thanks.