exhaust leak at Manifold-TTI 2 1/2 " downpipe

I had a lot of problems with my TTI downpipes on my 340. TTI was absolutely no help. They told me they use a jig, so there's no way that they could have sent me the wrong part. On the driver's side, the pipe was smashed up against the 727, and I had to modify it to make it work. I added a spacer that was about an inch thick between the manifold and the head pipe, and it put the pipe in the correct position. Sounds like I had a pipe that wasn't quite right to me. The passenger side leaked like you describe, but I sold the car before I ever dealt with it.