Adding a bit more information to the thread:
Throttle body 1-1129s is unique to the 2100s carburetor
Throttle shaft and arm 3-889s is unique to the 2100s carburetor
When the OP called, I suggested he look at the orientation of the throttle plate in the throttle body to make certain it was correct. Given the offset of the throttle body, if the throttle plate were installed on the wrong side throttle shaft's normal orientation, it could change the clock position of the throttle arm. Don't know that this is the answer, but certainly worth a look.
Jon
