Hi,
Ford specification, on gr N Escort preparation brochure tarmac, is
Front : 85 N / mm
Rear : 85 N / mm
But be carrefull with rear, because in grN, it is not coil over, and the ratio is different.
On grA Escort brochure, for rear coil over, Ford specification is
Rear : choice between 36 N/mm _38 N/mm_40 N/mm_54 N/mm

Regards.