What is the blue line's name and where should be connected (to five)

[Sonic]

Hi all,

I'm trying to put back the upper intake but I got confused what i marked on the pic correct or not what is the correct way?

 

[General karthief]

I think that thing the arrow is pointed at is the purge valve, it gets manifold vacuum.
The diagrams show the PCV system.

 

[Chythar]

Yes, you've marked the diagram correctly. Not sure what the difference is between #4 and #5 in the right diagram, but the hose goes from the nipple under the intake to the white connector that's circled in the engine photo. The #1 in the PCV valve diagram is the same hose (#3) in the diagram on the right.

 

[manicmechanic007]

Without a bigger picture it could be several things
It is possibly the HVAC vacuum supply line
Go easy on yourself and take a few pictures as you disassemble
You should easily see where it goes once you get the upper intake put back on
Do not get ahead of yourself
The VECI is your friend

 

[manicmechanic007]

Vehicle Emissions Control Information
The sticker under the hood with the vacuum schematic and cat info year etc.

 

[Sonic]

Vehicle Emissions Control Information
The sticker under the hood with the vacuum schematic and cat info year etc.v

mustang 1995 gt cab. Ive found images on web :/