The easy answer is to pull off the mag cover, on the upper right side there is a mark in the cases, there are also 3 marks on the stator assembly, standard has the middle stator mark lining up with the single mark on the cases. the difficult way is to use a degree wheel and a dial indicator in the end you will be at the same place, the marks should line up, that is unless you've sheared a key, have you checked that?