Ford uses Waste Spark, very first spark system ever invented, 1890's I think, super reliable, spark is based on the CRANK SHAFT position, not cam position like a distributor did
So each spark plug fires at each TDC(top dead center) of its cylinder, no it doesn't spark on exhaust stoke for better emissions, it sparks on exhaust stroke because its a Waste Spark system timed by the crank shaft
As long as both spark plugs fire in each cylinder then that's the best performance you can get from this spark system
