It would be good to determine whether it's missing under load (dist cap, wires, plugs, fuel issue) or dragging (caliper?).

I'd probably try to get it to do it on a down hill and coast to see if it slows more quickly that I remember. If not I'd focus on it missing.

Good usage "tugging" BTW. Captures an indeterminate dragging feeling
--
240s: 2 drivers and some parts cars

Not sure what you mean by tugging. Running on 2-3 cylinders with lack of power when accelerating from a standstill that suddenly smooths out at higher RPM indicates a bad distributor cap (and possibly dist rotor). If it's just a feeling that the car slows down on its own and happens after the car sits for a while, could be the parking brake sticking (if you're using it).

Zack
1980 245DL M46 291k
1988 745T+ M46 238k

I don't really know what you mean by "tugging" but "feels like it's running on 2-3 cylinders" seems plain enough. My first thought is a sticking caliper--you mention the car sits for periods of time. Try driving a short distance to make the situation occur--stop and feel the wheels for excessive heat. A little bit of radial runout in the rotor will force a reluctant piston back-- until the next time you apply the brakes.