Quickest access to a vacuum line on E34?

[theirongiant]

I am going to Seafoam my M50 engine, and I want to know the easiest place to access a vacuum line. Does the intake manifold have a suction hose just like the M20 engine?

On a related note, I read a BMW thread on a different forum where the poster removed his spark plugs and poured Seafoam directly into the cylinders and let it soak for a few minutes. Is this a good idea? How much Seafoam do I pour in? I expect that Seafoam and carbon deposits would come flying out the sockets as soon as I start cranking.

Seafoam really helped my old 3-series with the M20 engine; I'd love to give this one a good cleaning as well.

Any advice is appreciated.