hi guys quick question zetec silvertop head is it a tapered washer or one with a sealing crimp washer, i was on focus rs ones which have a washer but i have no way of knowing what is originally fitted to these zetec spark plug type silvertop

 

You need the iridium plugs either way if turbo.
The std frs mk1 plugs are not great for power.

Matt Lewis and Msd stock them. 46£ I think last time I bought a set was a week ago.

 

Duratec I4 Eco Boost check my thread on the misfire i got its drivin me mad!

 

As Jano said, denso iridium itv27 if running big power