1987notchback

so as it sits it should be ok? the reason for my concern is i thought one of these were possibly the cause of a vacuum leak that was effecting my idle. like i said before i have limited knowledge of what was done to the car before i got it. all i know for sure as far as the engine goes is it has mass air a cold air intake and def a larger cam. i understand that a larger cam can have a large impact on the idle, but the problem is not consistant.... i have had larger cams in previous cars and never had this crappy of an idle and even up until even 3000 bu then again it is not constant.... that being said i like to work on cars but i am def not a mechanic is it maybe just to big of a cam for my taste and i am over thinking it?