Thanks Lugnutz How 'bout a photo of your x pipe install, if it's not too much trouble.
Explanation time. I have an engine noise. Pretty sure I have a good ear. It sounds like an exhaust leak.
So my brain goes into diagnostic mode!
Manifold to downpipe donut gasket looked fine. Good seal. No change.
Next, I welded up all the nested pipes to seal up any small leaks. To do that most efficiently without taking ALL the exhaust pipe out, I cut pipe and used the pictured sleeve connection pictured in this thread.
Could the noise actually be caused by the X-pipe? Hmmm.
So I took the X pipe off (it had to come off for final welding anyway) and drove the truck with only straight pipe coming back from the manifolds. It was so loud that I really couldn’t hear the noise very well, but I could tell the noise wasn’t gone.
Next, I installed my glass packs with more straight pipe, but with the X pipe eliminated. I had to convince myself that the noise was not caused by the X pipe. No change.
Now we come to the personal preference decision. My preference versus what the neighbors like. The X-pipe was a very quiet exhaust system. No hot rod sound at all. Hardly a rumble, even with glasspacks. X-pipe video
I really like the growl with just glasspacks and no X-pipe. The noise is still there though. Next I’ll check valve lash and then I’m stumped because I checked the engine to manifold yesterday and didn’t find a leak at the engine. Factory GM ram horn cast iron manifolds. Noise is not present at idle (at least I can’t hear it) and is most noticeable at acceleration. Spark plugs are tan like wheat bread.
Pics show my X-pipe fab. The exhaust tubing is mandrel bent mild steel kit from Amazon (NOT stainless like I said previously). I’ll never tackle something like making my own exhaust again. Too much fiddle factor and took me forever and a week.
I still plan to use the connection sleeves but will wait until I finalize the exhaust. Currently it’s mocked up to exit just in front of the rear tires while I do diagnostic work.