We have a 2003, but not in a C30, so can't help you there.
The most common reversing gear
with an angle was the MS2, which had a 7 degree down angle. The engine was offered with a number of reversing gears, but I think if you're seeing an angle that's probably it.
You can get all the specs (which may help measure for yourself since no one has answered directly) here:
Enter "2002" in the "Engine Type" box and it will bring up all of the 2002 information (except of course for the service manual itself).