Please Help!

After Fitting all my parts left to complete my engine only had the Water Temp Sender that comes of the head to fit!

Cleaned out the thread then inserted the sender and tightend it up but the damm thing sheered off! So i am now going to have to drill out the remaining parts as there is no other way i can see to get it out! My Father and i have tried numoures different ways with no luck!

So basicallly what i am asking is!

Does anybody know the thread size for the Water Temp Sender on a CVH head?

Car is Xr2i 8v but think all the CVH's heads are the same.

Cheers

Tiller