Boost Gauge Install

I finally got my greddy kit installed today. Now all I need to do is install the boost gauge. The speedshop wanted $60 for the install, so I decided to do it myself. It's a autometer boost gauge, I'm looking at the instructions but can't figure it out? I thought the kit included everything, but it looks like I'll have to purchase a t-fitting. Any help anyone can offer would be great. Right now I have the greddy turbo, greddy intercooler and greddy bov type s installed. One last thing, I've havn't install a turbo timer yet, so when I shut off my car, I let it idle for about 5 minutes. I have a water temp gauge, when I park my car it's usually reading 110 to 120. When I let my car idle for 5 minutes it shoots to about 180. Is this still good for my turbo?

Ron