For the past 5 years I have been trying to seal these Sanderson headers from leaking. I have installed numerous gaskets from copper, to aluminum, to just silicon again as they recommend. I have been able to seal up the head gasket without problems. But I have had a terrible time with the collector gaskets. Believe it or not the aluminum gaskets have even disformed themselves and moved out on one side of the tri-angle.

Again for years I have been embarrassed with the "leaky" noise at the runs, but I simply wont stay at home. I have to go to the runs no matter what. And the more I try to hush them up...the louder they seem to leak. I recently pulled the headers out and found that part of the problem has been the welds are breaking loose around the collector where the four down pipes come together. Sanderson welds a diamond shaped filler to connect the pipes together and they appear to break loose there as well as almost all the way around the welds.

Please do not take this as a slam on Sanderson. I called them I they asked me to send them in for inspection which I plan to do next week. But I am curious if you have had similar problems with block hugger headers and may have a diagnosis why this is happening. I have checked the exhaust system and they are not too tight so there shouldn't have been a stress issue.
Sanderson suggested the headers are getting too hot as if the car was running too lean, but this is not the problem either. What else could cause this?

Any help is appreciated.

Troy