there are two dowelish things on the passenger side by the distributor hole.
Those are actually two smooth-headed bolts that hold the oil pump bracket to the block.
DO NOT REMOVE OR LOOSEN THEM!That oil pump bracket is aligned at the factory with a special fixture, and if it gets out of alignment it can cause the distributor shaft to run in a bind and break the shaft or wear out the drive gear and/or the camshaft gear.
Can you post a link to a photo of the driver's side of your block? If so, maybe someone who is familiar with 261's can confirm whether of not there's a dowel.
Jerry