consequences of using cracked exhaust manifold?

[Derek]

Hello eveyone,

I've got a '86 MC engine sitting here with a crack over the #4 exhaust
runner.
http://www.users.qwest.net/~daleep/audi/4ktq/crack1.jpg  42kb
http://www.users.qwest.net/~daleep/audi/4ktq/crack2.jpg  37kb

Archive searching revealed numerous threads on welding vs filling vs duct
tape.  1 and 2 piece manifolds were also covered, as were the pros and cons
of some aftermarket replacements.  Nowhere could I find out what happens if
you just live with the crack.  So I ask, whan can happen if I reuse my
current 5kt manifold?  My parts person got a really evil grin when I asked
her about a new manifold, and she said all it does is tick, nothing worse
(she drives a 5kt)  If the crack just ticks a bit until things warm up and
expand thats fine with me.  Opinions?

Thanks in advance!
-Derek
'85 4000sq  rebuilt w/cracked manifold
'86 4000csq  205K/mi probably cracked
'87 GTi 16v  no cracks