X2 with John. I think if you replace the original water pump pulley with the one supplied by CAA it would work. The inner sheave on the new water pump pulley would be used to go from the crank to the water pump to the generator as original (but probably with a shorter belt) and the outside sheave on the new water pump pulley would have a belt to the compressor (using just a single belt although the compressor probably has a double sheave).
Unfortunately this configuration will drive the generator, water pump and A/C compressor off the rear sheave of the crank pulley which is the damper sheave. The power steering is driven off the outer sheave bolted directly to the crank. I'd be surprised if the 50 year old rubber in the damper lasts very long before being destroyed with all that load (something they don't tell you).
The picture on the CAA web site specific to the 58-60 Tbird is using a factory A/C pulley COAE-8509-A. That would have 2 belts from the water pump to the crank and then to the generator and a single belt to their A/C compressor. With the factory A/C pulley you have to add a sheave to the crank for the power steering, change the single generator pulley to a dual and change the power steering pulley to line up with the new sheave on the crank. Plus use a new shorter fan spacer.
Actually from the angle on the second belt it looks like they have the second sheave going to the power steering - and maybe to the outer sheave on the crank - sort of hard to see from their pic. That would keep you from having to put a dual pulley on the generator and maybe if it works keep everything from being driven off the damper sheave on the crankshaft?????
I'm adding A/C to my non A/C car. Made all the changes above using the factory water pump pulley. The A/C compressor will be driven from the water pump pulley by a single belt but the water pump pulley now has 2 belts to the crank pulley and generator one being to a bolt on sheave on the crank and not just to the damper sheave. Don't know the number on the crank pulley but the new PS pulley is COAE-3A733-A.
A/C compressor not yet installed
Found another pic of the CAA set-up from a different angle - still hard to tell the belt config but that's definitely the factory A/C pulley. I believe the 61-63 pulleys will work as well but haven't tried one. COAE-8509-B