Need help ASAP as I'm building my engine as we speak.

Has anyone had to drill out the head bolt holes on their head for ZVH?

I've swapped my origional head for one modifyed to use a zetec headgasket but the reusable headbolts, which we fitted to the engine origionally wont go through my new CVH head! but they did before.

The bolts are too thick.

ANY IDEAS