Have you changed out the distributor for another even its not the 40b,
try another coil and condenser,also hot wire it from the coil terminal direct to the battery ,only run it for a short time as no resister will be in the circuit.
Rig gravity feed to the carb ,bypass the fuel pump,
Pull the plug wires out of the harness,
Make sure the terminal plates are not shorting out,
Rig up a remote coil, the old can type and if you haven got a remote adaptor for the distributor ,cut open a buggered coil and drill up through from the brush end and with a small bolt mount a socket for the ht wire to the coil.
It should not be that hard to work out what's the problem, some times they are hard to find, but always a simple thing. ,
keep us posted.
there enough brains on this forum to fix any thing.
Lawrie