The Z starter was the same as the 327/210hp starter. There wasn't anything high torque about it. They did the same thing with the battery - the Z used the smaller Y55 battery.
It looks like they had some rules about how much cubic displacement was required before the component was 'upsized' - and they didn't account for compression ratio.
That said, the starter and battery for the Z are not known problem areas, so their methodology seemed to have worked.