I have a Epiphone les paul and it has EMGHZ pick ups and i was thinking about getting EMG Zakk Wylde 81 & 85 Active Pickups. Does anyone know if there is a big difference in them.
There is quite a big difference depending on the amp you're using.
Fender American Special HSS Stratocaster
Ibanez 1987 Roadstar II Deluxe
Yamaha THR10X
Marshall JCM900 SL-X
Ibanez WD-7 Weeping Demon Wah
TC Electronic Polytune
Seymour Duncan Tweakfuzz
^^I wouldn't even bother with pickup swaps until you have a tube amp. If you've got a solid-state or digital modeler amp, you will likely not hear a difference in pickups.
Atmospheric dark metal w/ black and death metal influences:
(My Soundcloud page):

Pestilential Flood
Ok thanks, I had a great Crate tube amp back in the day I just got this one because its a good price.