I'm not sure quite which way to go, so I'm going to post two posts as options 1 and 2.
This will be for option 1. Option is to use a factory bracket with a single groove pulley on the compressor.
This will require driving the compressor off the PS pump belt, so 1 belt will be driving both. The idler pulley bracket came off of an FE equipped engine. I used a straightedge and am confident that the belt will clear the water pump pulley.
The bump has a 4 groove crankshaft pulley, and the AC/PS belt will be driven off the 3rd groove, leaving the 4th groove empty. The compressor will be mounted vertically and braced to the exhaust manifold, which is drilled and tapped to receive the brace bolt.
In these pics, nothing is bolted in. It's all just sitting in there.
I do have some concerns about this arrangement. I would be driving both the AC and the PS of one belt, so if the belt broke I lose both systems. I'm also concerned about the side pressure load on the PS pump bearing.
But it is the way the factory did it, right down to the brackets.
A shot of the side of the compressor, so you can see how it goes in there.
This is where the idler pulley bracket mounts on the front of the PS pump bracket
A front view of the setup.
This pic doesn't show it too well, but the grooves of the compressor, idler pulley, PS pump and crankshaft do line up properly.
A shot of the compressor brace.
A better shot of the pulley alignment.
Where the idler pulley bracket mounts at the alternator.
I'll post my second option, and ask your opinion in that post.