TR6 exhaust gasket problem

[Brian Day <1briand@mail.airmail.net>]

Fellow Listers:

My '73 TR6 has a nasty habit of blowing out the gasket between the exhaust
manifold and the two downpipes.  It seems to be an annual occurrance each
Spring.  Aside from imperfectly mating surfaces, any ideas what could be
causing it?

Thanks in advance.

Brian Day
1briand@airmail.net
73 TR6  CF9167UO