The cyl . head shows the numbers 06 72 on it. It could be a date stamp. If so, that could represent a late 273 or a 318 head up to 1974. The head number would be 2843675.
For each cylinder, the rocker with the pushrod bump on the left goes left. The bump on the right goes right. Just another way of saying what has been correctly stated.
The rocker shaft should have a square notch cut into it. It goes down and to the left side of both heads. This does not apply to adjustable 273 rockers.
The wide hold down rocker shaft washers are placed under #2 and #4 bolts of the 5 total. When installing the rocker assy. ,there will be some lifters that will be up. Put a spacer between the bottom of the shaft and shaft stand. Like a 3/8'' drill on each end. Snug all 5 bolts down. Remove the drills, And turn each bolt down 1/4 turn at a time until they bottom out. This prevents bending of the rocker shaft.
