I just noticed something - In the drawing of the engine at the beginning of section 5 it shows both intake pushrods in the outer lifters. Maybe someone here who has their valve covers off can chime in.
In the drawing on page 5-14 it shows the 12 bolts for the spacer as 25 mm
(0.98 inches) long.
I wonder if the shouldered bolts in your picture were designed for the rocker arm shafts.