Which plug for Yama a/m head?

[tor*p*do]

I put this head on my 6M6 to get 170 psi
I measured the plug threads and it is at ~ 18mm
Stock head is 10 mm for BR8-HS
So I assume I go to a BR8-ES (like the Kawi)?
Thanx

 

[surferdude345]

yes use the Es plugs if the holes are longer then oem