volvo dl runs great but feels like it's having a "hiccup" what it this?

first let me say thanks! i've been on car gurus before and you guys were just right on the money with your answers! hopefully i have the same luck twice...
i have an 82 volvo dl 4speed.  it has a relatively new engine, new hoses, belts, plugs, etc..and i'll be honest, i don't much about the internals of my car, or any car for that matter, i'm just repeating what i've been told.  she drives great but recently i've noticed that the car seems to be having a slight sputter in power as i drive in any gear.  the stutter is so slight i mostly can feel it through the gas pedal but it is notable.  i've also noticed that before i experience this slight hiccup, i hear a slight clicking noise.  i've been told that it could be because i have after-market electrical boots that aren't fitting properly, creating an electrical arc, but i'd really appreciate some other thoughts on what this could be..