I looked everywere, what the heck is the vacuum line in front of the distributer screwed into the intake manafold. It has suction so i just
capped it off. were does it go. Looks like a hose goes on it.

 

I believe it's used to supply vacuum to the HVAC system under the dash- to move the various vacuum servos that determine which vents the air blows out of.

On my 85 it went from that fitting to a black plastic vacuum reservoir (shaped little little tiny mailbox) on the firewall near the power brake boster. From the there a second hard plastic vacuum line came off of it, ran along the top of the firewall to the passenger side where it went through the firewall (along with the wiring harness) and into the pass. compartment under the dash.

If you're not getting vacuum to the HVAC controls under the dash I believe the default position in a 3rd gen F-body is that air will always blow out of the defrost vents up top.

 

It goes to here on my 85 trans.

 

I am sorry if I am hijacking this thread but I've been trying to diagnose why my 84 TA won't start. I've been told and suspected a few things. Among them a vacuum leak. I already know I don't have those lines connected. Thing is on my 84 which currently has a LG4/L69 hybrid has a hole for this vacuum line in the same place mentioned here, between the distributor and the carb. On the original engine (L69) the line was split. I know one line went to the carb itself. I have no idea where the other one went. Anyone here know? I don't have photos of that setup because the engine in it now is being split with a T connector.

 

Thanks for the info snd photo, what`s strange is i have a T off the black
tiny mailbox. I re,ove my stock ACf or now. I thought the winsheild
washer jar was hooked up there and then jumped over to the washer
pump. Someone must have screwed it up. I will try to post photos
tomorrow.