1974 duster 440 wont start HELP

OK i have a 1974 duster with a 440 it was running fine then just died on me ... after some checking i have no spark at coming from the coil SO i replaced the ballest resister, the module, the coil, still no spark from the coil, now i have a new battery in the mix .. still no spark . working on it today and was having my son trun the key i got one little spark ( i had the coil wire pulled and was grounding it) only one little spark...

ok here is my question i am at a loss . please anyone give me some ideas

i am going mad