Could be stress if the exhaust has a lot of free movement. Sounds like it could also be from the engine torquing?

yeah put in another exhaust mount.
seems it was just hanging there on one mount on each pipe.
didnt weld it up yet until I come back from San diego.
(gotta remove them both and tig em up nice)
But yesterday morning I tried some putty to seal the broken welds and Im simple amazed how good this stuff works.
i went driving around all day yesterday and went to the bristol cruise and the stuff held just fine.
Its called PYRO PUTTY 2400
http://www.caswellplating.com/aids/pyro.htm
http://i859.photobucket.com/albums/a...0077Medium.jpg