Flickering or pulstating Headlights

I recall 2 examples where the issue was the very last piece that one might suspect.... Ground cable from engine block to battery. Most notable story was the 68 Nova that belonged to electrician. No need to type all that here.[/QUOT

I meant to ask if the cable is bad internally how do you check it? The ground cable checks 0 ohms from battery to block. Any more ideas on this whole situation would be appreciated. Thanks a bunch.