Header Leaks??

Hey guys, signed up a while ago, but just now needing some advice. I have a '69 Dart with a 318 from a '72 Charger. The previous owner installed a set of "bargain" headers, which of course leak from the center two pipes at the heads. I'm friends with the guy and he tells me that this leak is common and almost all the headers leak....I say NO WAY!

1. Is this that common?

2. I want this issue fixed (of course) and I am trying to decide whether to just go with manifolds or go with a set of good Doug's headers.

3. If I go with the Doug's, how would I get the right ones to fit a '69 Dart, with a '72 318, hooked up to a '93 Automatic tranny?? Or will any '69 A-body set up work. I do have a mini starter, so that shouldn't be an issue....

Thanks in advance.....