Okay, it's Canon that Jet is on the East Coast now,
Jet spreads. Just like opium and heroin did in real life. It doesn't take a genius to take a load of Jet over the continent and establish a huge market with dealing drugs. 30 years is far more than enough to make Jet spread.
and that Vault 87 "mysteriously" had access to FEV, as well. What's decidedly not Canon is that there's any explanation for these things at all.
"Dr. Wayne Merrick
I'm told that Dr. Merrick is one of the brightest minds in the field of accelerated evolution, and apparently Vault-Tec agrees, because they've set up this Vault around him to suit all of his needs in the event that the bombs fall. All of his data and his work have been transferred to this facility from many important sources such as Mariposa Base, West-Tek and Vault-Tec Labs."
From Vault 87 Overseer's terminal.
Thus, 87 recieved FEV to maintain the experimentation program in case the bombs fell. Simple.
EDIT: Noting that he uses the verb "fall" in present tense, it means that 87 was closed before Octover 2077.
That can explain the different FEV model they use. It was older and less "good" version of FEV, while the "good stuff" was developed in California after 87 was sealed.