Hi there,
If you haven't already, check out this thread, and scroll all the way down until you find my post. I've asked a bunch of questions about this.
http://forum.grailtone.com/viewtopic.php?t=5987&start=405
But if you have the tubes already, just pop it in and see what happens. From my understanding, those plate current figures are meaningless, as the tube suppliers got those numbers with a different plate voltage than in our amps.
~trem