VALVE ASSY, Distributor Vacuum Control, 3 port, replacement, mounts to thermostat housing, See also 12A091-8A for more correct valve, 12A091-1A, 12A091-1 and 980-4 for installation tool, ** At idle, under normal engine operating temperatures, the distributor advance (center port) runs off of ported vacuum from the carburetor (upper port) which is 0 psi at idle, During extended idling, on a hot day, maybe with the A/C on, engine temps can start to rise, When the coolant temperature exceeds about 225 degrees, this valve closes the ported carburetor vacuum port and opens the non-ported vacuum (lower port) from the intake manifold, Non-ported vacuum at idle is normally high (12-15 psi), and this causes the distributor vacuum advance to advance the timing which results in an increase of the idle speed (about 100 rpm), spinning the radiator fan faster and drawing more air through the radiator helping to cool the engine, When engine temps reduce to a certain point, the valve closes and resumes using ported vacuum, None of this effects the engine while driving as the distributor is already running an advance to the timing as speed increases, **

Ported vacuum switch, 3 ports, 1/2" thread.

Suits the following:

1968-1973 MUSTANG 289, 302, 351C, 351W, 390, 428

1969-1973 MUSTANG 200, 250

1979-1979 MUSTANG 2.8L, A/T, CALIFORNIA, ID# D7AE-B1A

1979-1979 MUSTANG 5.0, M/T, EXCL CALIFORNIA, ID# D7AE-B1A

1980-1980 MUSTANG 3.3L, A/T, CALIFORNIA, ID# D7AE-A1A, A2A, B1A, B2A

1967-1973 COUGAR 289, 302, 351C, 351W, 390, 427, 428

1968-1970 FALCON (BEFORE 1/1/70)

1968-1971 FAIRLANE FAIRLANE, TORINO, 70 1/2 FALCON

1973-1974 F100 360, 390

1974-1974 F100 302, A/T

1974-1974 F100 302, M/T AND A/C

1974-1974 F100 460

1976-1976 F100 302, CALIFORNIA

1971-1973 F100 4X2

1971-1973 F100 4X2 360, 390, SUPER COOLING

1975-1975 F100-F350 360, 390, A/C

1971-1973 F250, F350 SUPER COOLING

1969-1972 BRONCO 170

1973-1977 BRONCO 302, ID# D7AE-B1A

1978-1979 BRONCO 8 CYL., ID# D7AE-B1A

Chrysler

Cordoba 1975-1981
Imperial 1971-1975, 1981
Le Baron 1977, 1979-1981
New Yorker 1971-1981
Newport 1971-1981
Town and Country 1971-1977, 1980-1981
300 1971
Dodge
Aspen 1976-1980
B-Series 1974-1977, 1979, 1984-1987
CB300 1974-1978
Challenger 1973-1974
Charger 1972-1978
Coronet 1972-1976
DW Pickup 1975-1977, 1979, 1984-1987
Dart 1973-1976
Diplomat 1977-1981
Magnum 1978-1979
Mirada 1980-1981
Monaco 1972-1978
Polara 1972-1973
Ramcharger 1974-1977, 1984-1986
St. Regis 1979-1981
Ford
Bronco 1971, 1980-1982, 1986-1987
Country 1967-1972
Custom 1967-1972
E-series 1970-1987
EXP 1986-1987
Elite 1975-1976
Escort 1985
F-100 1971-1983
F-150 1975-1987
F-250 1971-1987
F-350 1971-1987
Fairlane 1968-1970
Fairmont 1978-1980
Falcon 1968-1970
Fiesta 1978-1979
Galaxie 1967-1972
Granada 1975-1978, 1980
LTD 1967-1979, 1981-1991
Maverick 1970-1977
Mustang 1967-1980
Pinto 1971-1974, 1976, 1979
Ranch Wagon 1967, 1969-1970
Ranchero 1971
Thunderbird 1967-1981
Torino 1968-1976
Jeep
CJ 1972-1974, 1979-1986
Cherokee 1974, 1979-1987
Comanche 1986
J-Series 1973-1974, 1979-1987
Jeepster 1971
Scrambler 1981-1985
Wagoneer 1972-1974, 1979-1987
Wrangler 1987
Lincoln
Continental 1968-1979
Mark III 1968-1971
Mark IV 1972-1976
Mark V 1977-1979
Versailles 1977-1980
Mercury
Bobcat 1975-1977
Capri 1973-1977, 1979-1980
Colony Park 1969, 1971-1974, 1987
Comet 1967-1969, 1971-1977
Cougar 1967-1982
Cyclone 1968-1971
Grand Marquis 1975-1979, 1981, 1983-1989
Lynx 1985-1986
Marauder 1969-1970
Marquis 1968-1979, 1981
Monarch 1975-1980
Montclair 1967-1968
Montego 1968-1976
Monterey 1967-1974
Park Lane 1967-1968
Zephyr 1978-1980
Plymouth
Barracuda 1972-1974
Caravelle 1978-1981
Duster 1973-1976
Fury 1971-1978, 1980-1981
PB-Series 1974-1978, 1981
Roadrunner 1976
Satellite 1973-1974
Scamp 1972-1976
Trailduster 1974-1978, 1980-1981
Valiant 1972-1976
Volare 1976-1980