Per diem? International override (yeah, some 75 trips are international). Why 9.3% for state income tax? I don't believe that is average. I believe it is a lot highet than average. And if you are looking for exact numbers (you seem to be) why not calculate the impact of maximizing your pre tax deductions?
Also, why quit with the lowest paying seat in the lowest paying airplane? Why not do that for all seats and determine a mean for all 4000+ FedEx pilots. Over the course of 6-10 years, that will probably be a more useful number for a crew force in which a majority won't remain in the right seat of the 75 for the duration of the contract.