I've got the ceramic ones on my burb. I got mine from summit, as they were a few bucks cheaper.
Like the other guys, the collectors are close to the shackle bolt. No contact yet, but close.
There was an extra tab on the right header, on the flange that didn't clear something on the head. I don't remember exactly what it hitting, but I had to cut the tab off. I'd take a look to tell you exactly what it was, but I'm nowhere near the truck now.
And I ran them with the paper gaskets they came with for a while, but they started leaking so I just swapped to copper gaskets and haven't had a problem since.