cylinder head bolts

[Jahu]

Trying to decide if the cylinder head bolts on my GTL are stretched as there does not appear to be much leeway for tightening. After measuring the head, the bolt in situ on the block and allowing for the washer, it appears there is only 1mm for difference.

 

[Steve Hennessey]

I doubt if they are stretched - more like the thread holes in the block have debris in them so not giving you a true value.
It is so important to ensure that these holes are clean of debris and the threads are not tight before replacing the cylinder head (and this applies to all cars that use bolts).