dont give up cars are confusing by nature..i deal with junkpiles on a daily basis..there is a slight possibility that you were overadvanced and and that may have been your problem..retarded timing is more likely to cause a fast overheat than overadvancing, not that advance wont cause overheat but retard is more likely .are you disconnecting the computer control when your setting timing? the tan wire with 1 wire connecter by the firewall?