Default [Q] No reception in NYC Subway.. can i change baseband?

Hey Guys I'm in NYC and I'm having issue with reception. I normally would have service at the platforms of the C Line between 96th st and 59th st... even as the train is passing in the tunnel.
I've tested with ALL other phones, iphones, HTCs, Samsungs, i've been able to get reception but not with the Find 7 x9076 US version.. i'm on 1.2.2i using ATT

Is there any way to update the modem/baseband while on a different rom? Eventually I'll be going to CM11