View single post by JodyKerr
 Posted: 11-04-2009 02:51 am
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JodyKerr



Joined: 05-15-2006
Location: Tempe, Arizona USA
Posts: 217
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 I start with quality. I'm certain that 30 years ago, when these were new from the factory that the exhaust manifolds were perfectly adequate. Not great, or even good, mind you, but adequate. 30 years later they are very brittle. Th efacing plate (that mates up to the block) is generally fine, but the tubing quality, paired with 30 years isn't. The engles inside the headers means that any water that would/could collect did, and caused many headers to rust out from the inside. Additionally, 30 years of vibration causes a lot of stress on that tubing, resulting in cracking and stress fractures. To add insult to injury, they're very difficult to weld well because of the porosity of the tubing due to age.  Also, as was already mentioned, it's a royal pain to fit/remove these headers. (I've been there done that on all of these items with multiple exhaust headers)

Because of these items I'd be very leery of any factory header. You may be lucky and have one that wasn't used, or is from a very low mileage car. I would definitely spend a lot of time going over any original header before using it (and then only using it if I were trying to be either a) cheap or b) original). If you're going to spend all the money to have it ceramic coated, I'd also have it properly checked for stress fractures (like they do on engine blocks, etc).

When it comes to performance, all those bends and such in the stock manifold simply create a lot of back pressure on the exhaust. for every twist and turn it gets worse and worse.

If you're going to spend the money to do the coating process I'd highly recommend going with the performance headers from Delta. They're worth the money on ease of installation alone, plus they are good for a few extra horsepower because of more efficient routing (I forget what the claimed amount is).

Jody