My '68 w/302, 2 bbl carb. will crank with no problem but will stall and then stop for no reason. It will crank right back up most of the time with no problem. Have changed points, battery cables, and coil.
does not seem to be vapor lock, because it will crank up afterward with no problem.
Sounds like you may have a bad hot wire to the coil, or the ignition switch may be bad too. Ditch the points for something like a Pertronix unit. ASAP.