65 cuda

Could be a bad wire from the coil to the dist . or,if it's points the points or condenser could be bad or out of adjustment If it's points turn on the key to run and open & close the points with a screwdriver while holding the coil wire that goes into the center of the dist cap about 1/4 inch away from the block by bare metal using insulated pliers .If you get a spark there the condenser and coil are good so set the points to proper gap and it should work.