Used Buick carburetor rear vacuum fitting. This one came from a 2-bbl on a '64 Lesabre. Has the fittings for power brakes and PCV plus two unused ports that have plugs in them. I've seen similar fittings on nailheads and small blocks on both 2-bbl Rochester and Carter 4-bbl AFBs from roughly '63-'66. Usually though, I've only seen the fittings with all the extra ports on cars with cruise control. This is a very nice condition part with no issues.