Could be the ignition switch dropping power to the distributor while in crank position. Try turning the key to run and using a remote wire to run the starter. HEI is bad for rotor button problems. Just take the cap off leave the primary wires attached, hook a test light to ground and put the tip of the test light or ground wire will work too, about 1/2" from the coil tip in the cap and see if there is spark there. If so that means the rotor is bad.