Having trouble keeping my head gasket centered to the bore (a big bore 1390 with very tight gasket bore size to cyl bore size), I took 3- 8mm x1.25 hex socket head bolts 3/4" long, and turned down the socket head to .332, which is just a couple of thousands under the head gasket hole size. Put these in each end head bolt hole in the block and tighten till shoulder touches block, and one on the opposite side in 1 or 3 cyl. Lay on your gasket using these "locating pins', then place your head on. This holds the head gasket perfectly centered, as well as the head. Install the center cyl head bolts, tighten to the first torque spec, and then use an allen wrench to remove the 3 locating socket head bolts(might use a spot of tape on the end of the allen wrench to make it tight enough to pull the loose bolt out of the hole). Voila, centered head and gasket.