Also posting in the Doug Thorley headers thread as it relates to that product.
OK, I just got my truck back from having the DT headers installed. The installation went smooth but the repeated connecting and disconnecting of exhaust parts made my 14 year old exhaust gaskets basically disintegrated, and now instead of hearing the annoying ticking from the manifold, I'm hearing it at the flanges. A few of the flanges connecting the various exhaust sections were also rusted pretty bad, so I'm not sure that new gaskets alone will solve the problem. I kept the stock upper/upstream cats. I ordered all new exhaust, everything after the first set of cats, and have not yet installed.
MY QUESTION: My mechanic welded the cats pretty good, but any welding like that can never be quite the exact dimensions as original. While investigating the leaks at the flanges, I can see that when UNBOLTED, the flanges don't perfectly line up like stock, and are slightly askew, maybe a 1/2"-3/4", but I still have to muscle to two sections of pipe together to get the bolt holes to line up.
especially here, where this crudely drawn arrow is
With the bolts in, the two sections will seal together good enough, but I can tell that there is some tension when bolted. I'm worried that since our exhaust system is so solid with no 'give' anywhere, that the tension would or could be transferred to the manifold and cause new leaks in a hard to reach spot, or that the tension may prevent tight seals when I put the new exhaust in.
Curious if anyone has ever replaced a small section of exhaust pipe with a section of flex pipe? I'm surprised our trucks don't have any flex sections. Do you think it would be beneficial, especially in an offroad truck? Or do you think that new exhaust and new gaskets should cover everything? If I do add in a couple flex sections I'd like to do it while I have the parts off the car instead of dropping the truck at an exhaust shop again.
THANKS!
-Greg