Pulled pork per 8qt pan

Metal pans? How deep 2, 4, 6"?
A 2" inch deep metal pan will easily hold 12lbs mounded up.
If using foul pans you wanna stay to the 10-12 lb mark especially if putting into water table warmer. Foils pans will bend and flex and might drop into water table if loaded to much.

I think you will end up with more than 45#. Figure 60% yield on pork butts.