e36 cam timing
 

Hi Guys,
I am relacing my head gasket on my 1996 e36amg M104 engine.
My exhaust sprocket has two dowel holes. One of the dowel holes has a "U" stamped next to it.
My engine is not set up using this dowel position.
I would like to know how this engine was set up at the factory as I believe the head has been off before.
Thanks for any help.
Bob