hi guys, i have an h 400, and a line 6 hd 147 head, i was wondering if i should switch out the 59 jb combination for and
emg 81, and 90
i play mostly, death and black metal.
for example: necrophagist, 1349, behemoth, dimmu borgir, cannibal corpse

but every so often, ill use some cleans but rarely, will the line 6 cut out the emg fuzz on the clean channel

I would say 81/60 maybe. not too familiar with the 90. I dont find any fuzz with my emgs. so..
What kinda line 6 do you have? If you have a solid state then id suggest getting some good passives like seymour duncan JB/Jazz cause actives are best for tube amps and you cant really tell a difference when its put to a solid state
Your pickups should be fine for Necrophagist...But if you must switch em out go with DiMarzios not EMGs, EMG's will just suck out all your tone. You might as well be playing a plywood guitar if your gonna use them.
Sorry i missed the top part. Um H400 have seymour duncans already and i think they're pretty awesome for stuff like necrophagist and cannible corpse. If you really want to switch pups id suggest just going with EMGS but really its apples and oranges between duncans and emgs imo