The EFI v8s had point triggered transistor switching devices. If both sides of the points are always grounded, it sounds like a switching unit problem unless the wiring in between is shorted. Disconnect the lead from the distributer where it attaches to the switching box and check. If the switching unit is bad I would replace it with an aftermarket optically triggered system. The whole unit can be had for 150.
Bosch Master, ASE Master, L1
33 years MB technician