have you remembered to put the washers on the head bolts.
the bolts are quite close to bottoming out in the holes so without the washers you could have hit the bottom that will stop you tightening them correctly.

or could it be you have nt greased the bottom of the head of the bolt and washer and it is dragging on the cylinder head.

I did a complete engine rebuild with full bearing replacement and went down my own route route with head bolts not factiry and not over priced ARP struds, and have done about 7k miles since the rebuilt and have been running upto 1.5 bar boost and all is hold well.