Topic: 1974 Emission Question
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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As I am looking through pictures of 74 corvettes on Evil Bay that are supposed to be original I noticed that some of them have air pumps up top beside the AC compressor. Mine has no such pump but is a 74. Did some of them come through with pumps and if so why or why not all of them. I am glad I do not have an air pump but why? Or are the ones I see like this a different motor from original?
Thaks Rodney
Thaks Rodney
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Lifetime MemberModerator
Moses Lake, WA - USA
Joined: 4/16/2005
Posts: 2134
Vette(s): 1976 L48 4-spd, Mahogany Metalic exterior, Buckskin interior 350ci/350hp, 3rd owner, fiberglass spring, 255/50-16's Torq-Thrust II
I don't know for sure but the ones with air pumps may have had option YF5 which is the California emissions test. California all ways leads the nation in stricter emission requirements.
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
I think by that time all engines had the AIR pump factory installed. It's not unusual at all to find a car without it as many owners removed all the emissions related equipment over the years.
With many cars being correctly restored now the proper AIR pumps have become quite expensive to obatin.
With many cars being correctly restored now the proper AIR pumps have become quite expensive to obatin.
Lifetime MemberModerator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
'74 cars with automatic transmissions did NOT have the AIR system. The 4 speed cars did. 
Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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