Vibrasonic got my joke.I believe the OP was refering only to V1..
I tried it yesterday on my vibrochamp but it didnt seem to help the gain much.
It might help to know which amp exactly you are talking about. There are a lot of similarities between all of the Blackface amps, but if we're going to start pulling tubes, we may want to specifically identify which tubes (reverb driver, phase inverter, etc.) instead of just V1, V2, etc, or specify exactly which amp we're talking about. V4 isn't the same in every Blackface Fender.
Yes, pulling preamp tubes from a two channel Fender style amp is a way to increase overall voltage and gain a little headroom and power. When you pull the tube out, the circuit is placing less demand on the power transformer, and overall voltage will go up slightly. This is especially true of amps with marginally spec'd power transformers, like the Band Master.
No, the bias won't be a problem, because it will scale along with the rest of the voltages. We're talking about preamp tubes here, and there is no "paired" tube to worry about. Do not attempt this with power tubes.