For my further education, this metal tube that comes out of top rear of the intake, then goes forward and hooks to something with a rubber tube. There is no sealing on the intake end, just pushed in. The intake end is factory constricted. Only a small wire will pass into it, not the t pin. Form 70, 71, 72, 455 probably.
That would be my first guess, but it could also connect to a vacuum canister. The Buchev has one which I believe was OE on a '66 Nailhead. I wouldn't have put it on unless it was factory in either the formerly Diesel truck, or the engine.
The metal tube on the "top" fits inside the fitting on the intake, and the "rubber hose" on the top slips over the connection to provide seal and secure it to the intake fitting. The bottom of the tube just uses the rubber hose to connect the tube to the modulator nipple. The is a clip that snaps on the transmission filler tube and holds the metal tube in place.
