Used smog hose "T" connector. Connects the cylinder head smog tube hoses and hose to check valve. 1967 Mercury Cougar and 1967 Ford Mustang with 289 or 390 engines, and typical California Thermactor smog system. The 1967 Engine assembly manual states that this part has a number of: 379179-S, while in fact it is imprinted with 379169-S.
Ford part number 379179-S, 379169-S.