Well, in that perspective, O.K. I re-read my post and never actually gave a failure curve. Around here, we only get seasonal use. In the first year, they were repaired twice. repair cycles only went up from there.
I agree that failure is from fabricating/design. Thats why I stated that a few slip joints would probably saved or prolonged their use. With that said, heat cycles DO harden and shrink the steel. If that isn't taken into account in the design process, they will fail no matter who welds them.
Also... I agree with Fred. Headers might make more power on an engine that is maxed, but in my case I never even got close to that point.

I got to wonder why no one runs the turbos and / or headers out to the fenderwells? you could put the turbo behind the front tire and feed the hot side with a fenderwell or even a shorty style header.

Here is an example although it is not a Mopar. You could run the cold side piping in many different ways and keep the underhood area uncluttered.



Just a thought. www.dmcracing.com has a few all out race cars done this way. i don't see why this wouldn't work on the street with smaller turbos and some heat sheilds.