Its not from the Workshop manual its part of the IPB (intergrated Parts Breakdown).
These numbers would be the ones nissan uses to order spare parts with.

It's the best diagram ive found to explain the vacumm system for the 8 port JDM heads.

My understanding is that by default the ports are open, these close when the engine is not making boost (ie Vacumm from the manifold). Therefore as long as you have pluged the lines and run a vacumm line to the Fuel pressure regulator you won't notice high RPM power loss but theoretically you will loose torque at low load/RPM.