I have a stock 77 440 in my 68 W200. I knew that its been needing a tune up. last week it would not start. So I started replacing parts. I think it was a combanation of things that would not let it start. Its running now I changed the coil, balast resistor,voltage reg.,plugs and wires and cap and rotor it runs and drives fine but after running at idle for a few minutes it strarts running rough and eventualy kills unless I give it gas. I went ahead and changed the control modual thinking it was bad after it got hot but it still is having trouble. The only other electrinic part i can change now is the pick up coil in the distributer. But I'm think it could be a carb problem but I've never messed with a carb before.Is it hard to rebuild the carb? Any ideas?