Looks like the AMS V1 crank pulley to me in the writeup (image 10), whereas the Z1 pulley resembles the V2 Unorthodox pulley more which I think uses the stock belt size (A192M-42LSAVW). It's hard to know for sure when a lot of these writeups are two decades old, presumably before the Z1 pulleys came out.
I do have a Gates stretch belt tool coming in tomorrow to help me "walk on" the belt, but I ruined the ribs on a belt already trying it before without the tool. It's incredibly tight.