Seafoam - which valve to use?

[SnoqualmieE30]

Noob question: where's the brake booster('90 325i)? Like where should I pour in the Seafoam? I don't want to pour seafoam into the wrong hose... I can't find a labeled diagram of the m20 engine or anything!! Could someone just post a picture of where the valve is or something? That would be really helpful

[MR 325]

Any vacuum hose will work. If you're not sure where the brake booster is you may want to keep the hood closed.

I usually use the idle control valve hose and have somebody else keep the car running for me while I do it.

[SnoqualmieE30]

Thanks