Not adjustable i'm afriad, on a mk2 its auto adjusted and the most you can do is reset the adjuster. On a Mk3 its hydraulic and the slave cylinder is internal of the box bellhousing so you get what you get i'm afriad.
If its a mk3 there isn't even a cable, and you can't on a mk2.You can't even adjust the cable somehow?
IndeedI take it that includes the 197/R27 ?