This line comes from the distributer vacuum control switch and from the manual looks to go to the top port of the carb (firewall side). Problem is the choke stove already has a line attaching there. Any suggestions?

 

I can help, some.

Ok, the tee to the right is the dreaded TCS vacuum tree, and it sees coolant temp on the bottom, electrical from the trans on top, and the bottom two ports are ported and manifold vacuum, and the top port is off to the distributor. The idea is that you get ported vacuum when in high gear, and manifold vacuum if overheating, and no vacuum if neither of those.

On the quadrajet, the heat stove is not plugged into vacuum, it's plugged into fresh filtered air. Vacuum ports on the bottom of the carb are manifold, and they are identical to vacuum ports on the manifold, hence the name. These are below the throttle. Above the throttle, in the middle of the cab, height wise, is ported vacuum, which is still inside the carb, thus vacuum, but above the throttles. At the TOP of the carb, there is no vacuum, it's just a way to get behind the air cleaner for nice fresh air, which is what the heat stove is plugged into in the back.

To make the TCS work like factory, you need a ported source from midway down the carb body, and a manifold source from the base of the carb, or the intake manifold. Vacuum lines can be easily "tee'd" with a vacuum tee, but you should probably see if anything is jacked up with your vacuum lines first, like aftermarket stuff.

 

Oh that's very good.

 

Yeah. Get the correct carb that has two ports at the upper rear of the air horn, as used on the 1971-72 cars. Alternately, just run a tee like the 1970 cars did. This is just a vent line, it's not particularly critical.