Henry if you ever need dowels for a LB7 ,I have both head to block and rear cover to block on file its about a 30 bucks(CDN) for a set of 4 or 2 , but its done ASAP.
As long as it fits good in the block and head and sticks up far enough to position the head you'll be fine. And of course if the bolts or studs can go though it. Wouldn't worry one bit