Hi Mike.
Yes, I have performed a head gasket change before. It is a straight 6. I cleaned the head bolt holes to remove any trapped engine oil and to not damage the block when re-torquing the bolts.

I followed the three stage torquing procedure on the head bolts. (55 Nm, 1st 90 degree, 2nd 90 degree.

I removed the head again just now to inspect. I did notice that the head bolts did not seem that tight. At least not as tight as they seemed when i was wrestling with the torque wrench for the 2nd 90 degree tightening!