helicoil size

[datdrift]

i'm thinking of putting a t25 on soonish, but at least one of the head to manifold studs is gonna nees a helicoil, so i'm just wondering what size i need to get? is it m10 x 1.25 ??

[30psi]

It should be M10x1.25 but could be 1.5 if someone has buggered around with the studs before

[northerner]

Yeh defo M10x1.25 its funny that the studs have a different thread at each end though!