Problem with exhaust manifolds - should I get headers?

Hi folks. I have a problem with the stock manifolds on my 1994 Firebird V6 3.4L (auto). First of all, the car engine runs kind of rough, and it sounds like there is a manifold leak/crack on the passenger side. This
was confirmed by a muffler shop mechanic examining my manifold. He was not able to determine precisly the cource of the problem, as I would have had to pay them some money to attempt dismantling components in order to get to the manifold and do a thorough close-up examination. On the DRIVER side manifold, there appears to be a missing BOLT from the front of the exhaust manifold. Either the bolt is completely missing, or more than likely it broke off.
Because of these manifold issues, I want to get a brand new set of manifolds to replace the stock ones. A friend of mine is a GM mechanic and he can order me the manifolds at dealer cost, but I just checked GMpartsdirect.com and they have an even better price at $127 (US) a piece.
Should I replace my manifolds or just get a set of headers? Will the headers replace the exhaust manifolds, thus eliminating them from the scenario and fixxing my problems? There is a listing on eBay for Camaro V6 headers manufactured by Pacesetter starting at $217. The mechanic at the muffler shop told me he does not recommend headers for a V6... why, I don't know. Are headers overkill for a 3.4L V6, or should I consider getting them instead of ehaust manifolds?
Guidance and advice will be greatly appreciated. Thanks.
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The 3.4 vin S engine is a big league dog of an engine, putting headers on it would be a large waste of time---not to mention give you clearance issues and problems when you change spark plugs.
If nothing else, get a good used manifold from the junkyard, have it checked for cracks and bolt it on :). Done.
Joe--ASE Certified Parts Specialist & 10th Ann.Club Tech Director '80 Carousel Red Turbo T/A, 26k orig. '79 "Y89" 400/4 speed 10th Ann. T/A, 57k orig '84 Olds 88 Royale Bgm 2 dr, 307 "Rocket" (lol), 141k and still going.... '80 T/A project car...
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