What is this fitting for

[Otto cv23]

It's on my distributor. Should it have a hose attached to it',is it a vacuum line or a drain for moisture?  It's an 87 350 260 hp with the thunderbolt ignition.  I'm still having the problem with the motor. No matter what rpm I'm cruising at if I slam the throttle down the motor seems to stop for a second and then go's that can't be right also slow out of the hole.  Starts fine idles fine can't here any missing and no backfires and will run top end almost 60 with the right prop.
Thanks Guy's

[dorelse]

Are you sure its just that your carb's accelerator pump isn't giving the motor the extra shot of fuel it needs when you slam the throttle down?

To me...that's what it sounds like.

[carlsoncvx18]

That is a vent no hose attached.

I think you are experiencing the q jet carb maybe needs a good cleaning. 

Every tank run a couple of cans of sea foam thru it.

[Terry_Curran]

Factory q-jets are famous for the lag you're talking about.  These mods willhelp get rid of the lag.  You can order new hangers and metering rods, manufactured by Edelbrock, from Summit or Jegs.

http://forum.cgoamn.com/index.php?topic=3757.0.

And that fitting you're asking about, is not for vacumm

Good luck.

Terry