If I recall correctly, the tubing is 2" to the cat, and after the cat it changes to 1.75". I am currently running the SVT exhaust which is 2" catback then split to 2.25" piping when it branches out as duals. (I think those are the right demensions)
As for the engine size,1L = ~1000cc, so 1999cc sounds about right. You should be fine up to about 2.25" piping all the way through. Anything more than that would probably cause a decrease in performance.
HTH
