Miloburnz

I am converting a 5.2 Magnum to V belts , i have fitted the timing housing and pump from a LA318 i have which also has an alternator with a double pulley but no other pulleys came with this engine when i bought it. I did find locally a aluminum water pump (2 groove 6 1/2") and crank pulley (3 groove 5 1/4) that needs slight modification to fit. My intention is to just run with alternator/water pump and when its all running ok fit A.C. later on, power steering as its a custom build its too tight to fit so leaving that for now so the third groove on the crank pulley will not be used i guess.

What would the normal pulley set up be with and without A.C. ?
Why has the alternator pulley got two grooves, i see the double pulleys are advertised for A.C. engines?
V belt size, is it an 'A' 1/2" wide belt ?

Any photos would be helpful