AZKen; I remember this post here...
https://6066gmcclub.com/showthread.p...uburban&page=5
it's GMCNUT's Kool Suburban with all the goodies your looking to add.
Per one of the last posts he mentions that the AC was a double groove with a bolt-on single groove for the AC.
I'm not sure if they all did it that way, but his was set up like that.
Here is a photo I have from an eBay listing of said lower pulley and also the upper and lower double groove pulleys from the archives.