if the barrel is threaded just need a .silencer with a hole big enough for a .311 diameter bullet. if the barel isnt threaded you can have it threaded at additional cost. there isnt a "special" sks only silencer if thats what your asking.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent