Sorry they got upside down but if you need any clarification on a picture just let me know.I see one difference between your module and a duraspark 1 is the wire running from R on the ignition switch on the black module goes back inside the module and has a voltage dropping resistor and the duraspark 1 has a wire not going inside the module and doesn't have a dropping resistor..I am not sure if the 77-81 duraspark has a resister somewhere else.Also you don't have to buy a module from ebay since you can pick up one from a good parts house.I didn't see anything but good solid info on the other posts.Good luck