What is this?

I doubt that tall vacuum tree is correct for a 1972 slant. I parted a 1974 CA slant (more emissions stuff) and picked another at a salvage yard and recall just a stubby intake vacuum fitting with maybe three 1/8" nipples plus a large top nipple for the brake booster. Whoever connected the large hose to the carburetor's large tube (meant for PCV) probably did so because "same size", though is also just looping the hose since both tap full intake vacuum.