I'm in the middle of doing this on my 351W.
I'm using:
*A 5.0 Mustang reverse rotation aluminum water pump.
*5.0 Mustang crank, alternator, and water pump pullies. (Stock, not underdrive.)
*P/S pump, pulley, and aluminum bracket from an '89 Lincoln Town Car, which mounts on driver's side, right next to the fuel pump (they use the 2-belt setup on the 5.0).
*The 351W's stock alternator bracket ('84 F150), which mounts to the passenger side head, up high next to the thermostat housing.
*The Mustang alternator pulley fits either the Delco 10SI alternator I rebuilt for one-wire operation or the stock 351W Ford alternator (and they both fit the stock bracket). I may end up using a 3G 130 amp alternator, have to see if it fits the bracket or not.
The 5.0 Mustang 4-bolt crank pulley needs to be spaced out 3/8" from the late 70's 28 oz balancer I'm using, but everything else lines up perfectly, and looks stock. The serpentine belt will run from the crank pulley up around the water pump, over to the alternator on the passenger side, then over to the P/S pulley and back to the crank pulley. No interference with anything, and plenty of belt wrap around all the pulleys. Belt adjustment will be by moving the alternator in it's factory bracket.
Here's more detail:
http://www.mcguill.com/Bronco/tech.htm