I'll tag on to this old thread in the interest of having one place for future owners to find info on exhaust alignments.
Troubleshooting a rattle/bump noise that just started happening on my '69 280, I found that the center (forward of the first muffler) clamp and rubber rings are missing. But the larger issue is that the whole exhaust is mis aligned in the floorboard "channel" for the pipes. The noise is from the pipes hitting the inboard "ear" on the floorboard that the missing clamp is supposed to hang from via one of the rubber rings. The forward part of the system is too far toward the center of the car. Farther back, the alignment is even worse. What is odd is that the rear muffler is fitting near perfectly in the rear quarter "pocket", all mounts and rings in place.
There is no evidence of hack work, the whole system looks fairly new (I only bought the car last Nov) and at least the forward muffler is stainless. All of the connections are U bolt clamped, nothing welded.
Oh, and one other piece of pertinent info, last month my wife turned into a drive way and dropped the right rear wheel into a hug pothole. The rear muffler took a good what but I can't see anything bent, gouged or torn. And the rattle didn't start until last weekend, but the missing clamp could have only fallen off then (if it was ever there to begin with)
Anyway I don't enjoy doing exhaust work at all, but my pipe dream is that I can loosen all of the U clamps and maybe wiggle the thing back into alignment. I'll make note of the tip above to watch the exhaust manifolds up front. Hopefully all of the joints will at least loosen up enough to move around a bit.
Anyone experience/fix such a thing before? Common problem? If I have to remove sections/mufflers, I'd probably just unbolt it from the exhaust manifold and drop the whole thing down and out from under the car to work on it. How much clearance is typical where the pipes pass under the rear swing arm?
Any tips appreciated. Not sure when I will get around to messing with this, but I will take pics and post em up in this thread...