I currently have a Schecter damien 6 with stock EMG hz passive pickups.....I want to install EMG 81/85 actives....is that possible?
in a word......yes, but you will need to upgrade the pots to accommodate the actives.
Running through:

Engl Fireball
Engl Slanted Cab
Ibanez Xiphos
Schecter C-1 FR Black
Ibanez GRG (on its way)

Boss Noise Gate, Zakk Wylde Overdrive, Boss Tuner, Zakk Wylde Wah.
yes, just will need a battery compartment (i believe... i'm really no expert with actives, i'm 100% on the passive pickup sound) and new pots.
Belief is a beautiful armour but makes for the heaviest sword.