What is minimum electrical required to start my car?

the short answer is this. you need positive to power the coil which is hooked to a GM hei module which is hooked to the distributor. second , power to the starter solenoid and starter. third is fuel. ground everything to the block. this is how I broke in my 440 chained to the floor of a 30 ft. trailer . as long as the timing is good it will run as long as the battery has enough juice to supply the coil.
yes first time, long ago before nephew touched it... run a wire from battery str8 to the coil to start it