DAL Bases are:
ATL
CVG
LAX
NYC (EWR/JFK/LGA)
SLC
My understanding is that there are pilot positions for all aircraft at every base, with the following exceptions:
777 - Only ATL and NYC
MD90 - Only SLC (Formerly DFW)
Delta used to have pilot bases in BOS, MCO, DFW......they've consolidated in recent years.