bumblebeeS2K

Have an Invidia N1 Dual sitting in my garage waiting to be installed after turkey day. Looking for some quick advice:

-I tried dry fitting the y-pipe and each muffler and it seemed like a pretty tight fit. I'm assuming that the y-pipe ends go into the pipe coming from the muffler. Do I need to use some silicone spray, liquid wrench, etc.?

-Is it best to attach the y-pipe and the mufflers before bolting it up to the car?

-Are there any torque specs I should be tightening the bolts too?

Thanks in advance.