Where is the best place to connect a vacuum gauge on a k12rs?

[SweetT]

I am trying to diagnose the condition of my vavle train and I know this can be done with a vacuum gauge. Where is the best place to connect it? I would imagine somewhere around the throttle bodies, but there are so many wires and hoses around there that I would hate to disconnect any of them and then find out there wasn't a nipple to attach my vacuum gauge to.
Any suggestions?

Its times like these i long for my old K75.