I am beginning to think that part
>of the problem is that there is too much weight on that particular part of
>the exhaust system.  It is from S&S.  The only support is from where the
>pipes are bolted to the heads and from where the muffler is bolted to the
>frame.
>
>John Lauterbach
>Macon, GA
>1984 DL

Note that all the rear engines are designed with the complete exhaust
system secured to the motor only. If you are fastening the muffler to the
chassis frame, that may be the problem. The motor will naturally move in
it's mounts and if the muffler is fixed to the frame you will be flexing
the pipes and besides working bolts loose this will in time crack the
flanges and or pipes. A flexible hanger for the muffler to the frame could
improve this but the solution is isolation from the frame of the exhaust
system complete. Could be just one more example of a problem with
functional installation of non stock parts.

And I know it costs more, but timed inserts are a much better thread repair
than helicoils. Both require considerable skill to install with precision.
It is almost impossible to find dead center and maintain true alinement
with a hand drill. On an exhaust port stud, it wouldn't have to be 'out'
very much to add to your problem.

T.P. Stephens aka Doktor Tim
San Juan Island, WA