Jeez man… I asked a simple question. I’ve already ordered them just trying to obtain data. Sorry to have bothered you.
Why did you get upset? (by saying JEEZ MAN?)
I know you asked a simple question, but it is obvious that no one here has the answer (about the diameter) for you (at least not until today). So I don't want to feel your question was being ignored, and just try to be a good host of this forum.
You did NOT mention that you ORDERED the D200 silencers when you started your post, so I did not know that you had already ordered them.
Normally, it's best to find information first before you order something... but since you already ordered it, then (from what I see), you only have 2 solutions:
a. Either return it, (or resell it on eBay) if it doesn't fit, or...
b. Modify it to make it fit.
(Thus, my response about me grinding to make it fit or making an adapter pipe (for my 998) is even more relevant to your current situation, where you already bought them).
Here is why,
I checked the ID spec online and double-checked with the Termignoni distributor before I bought my Termignoni Silencers. They gave me their ID measurement for the universal Termignoni silencer. Based on this information, it should be a tight fit, so I ordered.
However, once it arrived, it did NOT fit my SC-Project WSBK exhaust pipe, and I needed to do some fine grinding to make it fit. Yes, my experience was based on 2 different brands, but in theory, it should not matter much if I received super-accurate ID information.
I want to share this possibility with you based on my experience with Termignoni.