NEED HELP! Vacuum issue

[sugarandopium]

I tried to tee in my boost gauge in a stealthy place right next to the firewall.
Totally backfired on me as it wasn't a line that saw boost.
As I was piecing things back together I broke this T, Fitting, thing.
Circled it in the pics below, the top part of it that connects to the small line broke off.

What is it, what do these lines do, can I get a new one anywhere, and or can I just use a regular T in it's place?

Second pics arrow points direct to the plastic piece in question.

 

[DailyDrifter]

Its a check valve, Not sure where it goes.

 

[BlackMetal]

This looks like it to me:

eBay Motors: 1986 1987 Buick Grand National Vacuum Check Valve (item 260280144487 end time Apr-24-09 10:19:03 PDT)

 

[sugarandopium]

Wow, thanks, i had no idea kirban had it!