In another post I wrote, I was told that the NYS&W acquired three SD70Ms, but couldn’t afford to keep them, after they lost the stacktrain buisiness. Was that the same reason they got rid of the B40-8S?
You are confusing two different stories! 
The SD70’s had nothing to do with the stack trains…
Susquehanna bought the three SD70’s new from EMD in 1995…
they used them for about 5 years, then have been leasing them out for the last 10 years…they lease them because they can make more money that way…it has nothing to do with “cant afford to keep them”…the SD70’s have been making money for them! the three were just recently stored.
The B40-8’s are a different, and totally unrelated story…the first 4 arrived in 1988…
then 20 more arrived in 1989, CSX helped finance them, they were used to operate the D&H stack trains over the southern tier main, between Binghamton and Buffalo, because NYSW was running the D&H at the time…only 2 years later, in 1991, CP took over the D&H and NYSW lost the stack train business…20 of the 24 units were then returned to CSX, where they still operate today…
the remaining four stayed on the NYSW roster until 2004-2005.
More info here: http://gold.mylargescale.com/Scottychaos/susquehanna/
Scot