Firing order has nothing to do with the mechanical operation of the dist. Yes the firing order changed on all 5.0 engines made after '86. The firing order on all Ford small block engines (5.0 and 5.8) from '86 to the end of production was the same. Firing order is determined by the cam. in '86 and later it is 1-3-7-2-6-5-4-8.