12FV7 in a long-tail phase splitter on 18 watter

[AC-128]

Hi everybody!
I've recently found a 12FV7 tube. http://hereford.ampr.org/cgi-bin/tube?tube=12FV7
The pinout is identical to 12ax7, however the current is much higher.
Would it work with the original resistor values in the phase splitter?
Would the currebt gain overload the inputs on the EL84s?
And a general quiestion, will the signal become just louder? Because as I understand, headroom is concerning the voltage, but is there such thing as current headroom?
Thank you.

[AC-128]

Nevermind, guys. I tried it, sounds a little louder and more dynamic, but the thing is too microphonic. Constant ringing feedback which disappears once I put my hand on the tube.
Well, so much for my quest.
Take care and all the best!