I was looking up parts for my 89 300TE and just noticed there are two different exhaust seal rings, one for the left and a different one for the right.
Is this correct and if so what is the reasoning behind this?

I have had a slight leak so I crawled under to check and one of the exhaust flanges was crack and it appears that the same seal ring (the solid one) is used on both sides.....Could this be the reason it is cracked?

I also need a flange now but I cannot find the one I need....there are two halves, one that is threaded that you turn the bolt into and the other that is not threaded and has a slightly larger hole so the bolt will easily slide through.
I believe it is the non-threaded side that I need (I will double check today)....any ideas on where to get one?