Normal plate idle current is about 100-200mA, but of course you can change this with the bias. Offhand I would think 650mA Ig would blow the grids out of the tubes, that far exceeds their max ratings under full drive condx. You're likely measuring cathode current, which is Ig + Ip combined. Something is miswired. I doubt the tubes could withstand 650mA Ig at all without vaporizing pretty quickly.