What is the firing order of a 89 f350 with a 351 motor?

1 - 3 - 7 - 2 - 6 - 5 - 4 - 8

The distributor rotor turns COUNTERCLOCKWISE

The marked # 1 position on the distributor cap faces towards the REAR

The engine cylinder locations are numbered :

firewall

4 - 8

3 - 7

2 - 6

1 - 5

front of Ford F-350 ( V8 )