Rocker Shafts- Washers?

The bolts are all the same. The hole up through the shaft is sized to allow the oil to feed up around the bolt shank. I did find that one set aftermarket shafts had smaller holes at all points including the oil feed point (2nd stand from the left when looking at either head).

Big mounting holes in the shafts allow the shafts to shift each time you install, making consistent setup of the shims difficult. So it may behoove you to make some marks on each shaft and 1 or more stands on each side to align the shafts in a consistent position each time, so the shims and clearances line up the same each time.