wait is that a hard line?

 

im fairly sure it goes to the stocl intake tube. i had to pull it off mine when i removed my tube

 

Mine connects to the intake tube (before the throttle body). There doesn't seem to be much effect plugged or unplugged. I would either clamp it off... or if you are feeling handy, just put a vacuum nipple on the intake right there. I think it is used to detect and adjust the fuel mixture under high differential vacuum situations - ie, drop the throttle closed at 5000 rpms.

 

That is the fresh/filtered air supply for the starting air valve. The stock intake or a good aftermarket intake will have a nipple for it. Leaving it open is fine, or you can trace it back to the valve and remove it there. Or just remove the whole valve, it won't really matter....

 

o ok cool thanks