Exhaust Manifolds vs Headers

[Tryon #3185]

Have just removed the right and cracked exh. manifold to replace a blown exh. gasket and a few busted studs. I have recently learned that if another manifold is installed it will soon crack also and that headers is the way to go? We are currently researching the many coments in the ACOC Data Base on the subject. I would appreciate hearing any information pro or con on the subject along with any costs, part numbers, etc. Also of interest is information on the installations of headers that have age and milage on them, do they rust out, burn thru or crack?  Thanks, GAT.

[mollerus]

Gary,  
Although the right exhaust manifold seems to burn out faster than the left on the 440 it is not uncommon for 25 yr old manifolds on other makes to also burn up too.  I've burned out both manifolds on a 72 Chev 350.  I don't buy the story that a replacement manifold is doomed to burn up or break. However the face of the manifold should be resurfaced at a machine shop prior to installation. Blown gaskets and broken studs are a cause for manifolds cracking. A manifold literally runs red hot on prolonged trips especially under the heavy stress of pulling our 8000 pound plus gross weight. Headers do the same but cast iron holds up better to the prolonged high heat. The type of stainless steel used on headers can actually rust, especially at the welds.  The heat output around the junction of the dog house and the floor boards is higher with headers and can become quite unpleasant. Remember that the manifold/header is just inches away from your right foot! Used cast iron manifolds can be found in junk yards and will probably last for years.  I've seen new replacement right manifolds on eBay for about $100.00.  I'm not convinced that any increased power or gas economy with headers is worth the cost or the hot foot.