.016 pickup to reluctor gap. To check the pickup, crank the engine so that the rotor stops with one of the 8 reluctor points just about to pass the pickup point. You should now be able to advance the rotor with your fingers so that the points cross each other by the advance weights fighting against the springs. Pull the center cap, plug wire and lay the end within 1/2" to a valve cover. Turn on the key, then start flipping the rotor side to side quickly. It should spark everytime they cross.
Use a test light first and make sure that the light is on when touched to the + side of the coil!