It's kinda hard to make out: The first pic shows 1975/79 Econolines. The second 1978/79 F100/350's. Notice the difference in the P/S pump compared to the pump in the third pic.

Third pic: Since the 351W was not available until 1981 in F150/350's & Bronco's, y'all should not go by pics of F100/350's if a 351W has been swapped in. It will be similar only.

And...the OP is using a 351W from a 1969 Passenger Car. The arrangement will be similar only.

NOTE: The parts with the basic number of 8678 are the idler pulleys.