Pinking/Plugs for missus' Ford Ka Rocam

[evilkarnival]

Hi,

Just changed the plugs in the missus' '57 plate 1.3 Ka with recommended ones for the engine type (Bosch HR8MCV+) but the plugs I took out marked with both FoMoCo and a Bosch logo had a different part number (HR8MEV, I think).

The car drives OK but for the first 5 mins when it is cold, it pinks under load.

Wrong plug type?

Thanks for any help.
D