I splurge and use the Speedway $23 unit on the GM pump but if you like the idea of a Ford pump then all the later ones with the plastic can are very small in physical size and super easy to mount. Pick one of the tapped holes on the front of either head that positions the pump where you want it (usually the right side) and drill that hole out to where you can tap it to 7/16 which is the mount hole size in the Ford pump. An alternative is go to an alternator rebuilder and get a sleeve to reduce the 7/16 hole to 3/8 and leave the hole in the head stock. Screw a temporary long piece of all thread into the head and stack washers on it till the pump pulley is in line with the crank pulley and then make a one piece spacer equal to the total of the washers. Use some 1" by 3/16 strap to make an adjuster arm and that's it. Ford just used the one 7/16 bolt for the pump to mount/pivot on so that's the way I do it instead of dropping down to the smaller GM bolt. That long of a 3/8 bolt tends to flex a bit. If your good at fabricating you can cannibalize a section out of the Ford factory bracket that will put the mount bolt in double shear.

Evan