Presumably the 4.2 is the same as the 3.8 in that respect, otherwise they would have noted the difference.
It’s a bit odd that they don’t show the hydraulic circuit in the shop manual. They took the space to show the section drawings of the Dunlop pistons, which by that point were pretty well know (perhaps not in the US and Canada). In my opinion, a hydraulic circuit would be more informative. Perhaps it was just too expensive to have a draughtsman draw the new arrangement.
Here’s the one from the E-Type:
And here the 420:
