I bet you could use a ZX2 lower timing pulley. Its roughly the same size. If you buy any Zetec timing kit it comes with one, but is not used in the Focus.
FocusXtreme - Hatch Nation #96
04 ZX3 5.0, T5, 4 lug 7.5 w/ 3.73s [3/13 ROTM] ["Best Non-SVT" FITF '12]
12 SE Hatch Sport & Winter Package, ST Front End
91 Ranger XLT 3/4 drop
89 Bronco II XLT Well the body is still stock, what's left of it
97 Mountaineer 5.0, AWD, 3.73s