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Username Post: Rare 327 Intake Manifold?        (Topic#368308)
Posts: 710

Age: 70
Loc: Slaton, TX
Reg: 10-01-07
05-01-22 05:08 AM - Post#2840517    

I have a cast iron intake manifold casting number 3872782 date code E116. It also has a large H cast just below the firing number. It is a square flange intake for a Holley. It does not come up on any if the casting number lists I have found. It looks identical to another 1966 intake with casting number 3872783 which shows to be for a 275HP 327. Can anyone shed some light on this?

'38 Chevy Coupe Gasser 409 powered
'50 Sedan Delivery 401 Nailhead powered
'62 Buick Electra original survivor


Posts: 710

Age: 70
Loc: Slaton, TX
Reg: 10-01-07
05-01-22 07:52 AM - Post#2840520    
    In response to lobucrod

I made a mistake on the above post. The casting number on both manifolds are the same ending in 3. So both are for the 66 275 HP 327. So what is the significance of the H cast below the firing order?
They look identical otherwise.

'38 Chevy Coupe Gasser 409 powered
'50 Sedan Delivery 401 Nailhead powered
'62 Buick Electra original survivor

Frequent Contributor
Posts: 1406

Loc: Orlando Florida
Reg: 07-09-18
05-01-22 01:09 PM - Post#2840540    
    In response to lobucrod

Over the years I've seen lots of casting numbers with special characters in or around the area of the casting numbers. No one except the casting plant in the day knew FOR A FACT what all of that meant.

The stories that I have been told by those of the era were that some parts were actually cast by outside companies to make up for capacity issues. Those were marked indiscriminately so they knew where they were cast.

No one knows for sure unless they were there running the casting plan and have original records to back up their story.

People fear change because it threatens what they know, or what they claim to know.

Valued Contributor
Posts: 3969

Reg: 04-15-05
05-01-22 03:49 PM - Post#2840554    
    In response to lobucrod


Pass, Chevelle, Chevy II, 1966 327, 275 horsepower, w/A.I.R., 1966 Corvette

Corvette, 1966 327, 300 horsepower

"This intake accepts either a Carter or Holley carburetor depending upon specific application. This is readily seen by identifying he multi-carb mounting flange. It uses regular carburetor studs. This intake was also used extensively as a service replacement".

Dedicated Member
Posts: 5551
Loc: Lake Superior-Michigan US...
Reg: 03-30-00
05-14-22 02:26 AM - Post#2841181    
    In response to lobucrod

Holly carb.

327, 275 horsepower, w/A.I.R (smog engine)

A.I.R. = Air Injection Reactor (CA emissions). This pumped air into the exhaust manifolds to reduce emissions. In reality, not a desirable feature and many were deleted by owners.

Used on vehicles destined for sale in states like California who had strict emission regulations at the time.

  • Quote:
The General Motors Air Injection Reactor Air Pump 660108
1966 models of General Motors passenger cars and light trucks sold in California are equipped with the General Motors air injection reactor system. This system meets standards for control of exhaust emissions. Saginaw's contribution to this system is the air pump, which supplies supplementary air for the injection system.
The Sagniaw air pump is a semi-articulated vane type pump of a positive displacement variety. The pump has a design displacement of 10.3 cu in. per revolution with high volumetric efficiency and low horsepower consumption. In the development of the pump, it was necessary to establish durability requirements consistent with the life of the vehicle, providing satisfactory performance without maintenance. It was necessary to perform laboratory tests to insure compliance with these requirements. The Saginaw air pump satisfies all the design objectives and has been accepted for use on 1966 vehicles sold in California.

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Mel Foye 
*VIP* Original Founding Member Group
Posts: 5423
Mel Foye
Reg: 09-29-00
05-14-22 08:45 PM - Post#2841212    
    In response to elcamino

Boy I would have lost a lot of $$$ betting on how much air that could move, that is a bunch.

It Was On Fire When I Laid Down.


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