Wilson....I have split the upper a-arms on the axis but not on the Mission yet with them in the inline pos. Its b/c you hit something and they break right there on the back side of the upper a-arm. If you dont run in-line then the arm does not break but the tie rod might snap...Have had this happen too. They are working on changing the mold and putting more material around the threads of the upper a-arms so this does not happen as much. They did change the mold when they went to the new upper a-arms on the mission but its still not enough.
I like the 20t pulley better.....the drive train feels much better with it installed then the 17t. Also with the 17t pulley the car just seems to spool up and never run down the straights on like a 75ft. or more straight.