I don't know who the hose is. But the one in the hand looks like its going to the back of intake. It's for the PCV.
Thats the PCV hose that attaches to the large nipple on the bottom of the front of the Q jet.yours is broken you need a new one.TA repos them. gary
I hope that there is more than one company reproducing those or they decided to make it correctly because I bought one from a well-respected parts supplier and it wasn't even close to being correct. The supplier called the manufacturer and was told to drill out the ends so they would fit in the PCV valve and the carb fitting. What a joke!
PCV, Positive Crankcase Ventilation. Blowby from combustion gases that get by the rings causes pressure build up in the crankcase. The PCV system evacuates the crankcase. There is a vacuum nipple on the front of the carburetor. A hose (the one in the picture) connects there, goes around the passenger side of the carburetor, and connects to the PCV valve at the back center of the intake manifold. You can use regular 3/8" vacuum/fuel hose. The stock line is formed, but you can use regular hose, it just doesn't look as neat. JiDubbelve , Do you have a Buick chassis manual? If not, it should have been the second thing you bought after the car.
I purchased one recently from. McIntyre Enterprises. $18 + ship ($6)! http://www.buickperformanceclub.com/1970PCVHose.htm
Make sure the pcv valve rattles. It could be stuck after being installed for such a long time or replace it. They can be internally cleaned with carb or brake cleaner. Also the general condition of the other hoses looks poor. Now is a good time to replace hoses and tubing that will cause a lot of problems if left alone. Good luck