There have been several threads concerning the use of flange (mounting) gaskets when using Carter YF carburetors on Chevrolet engines.

Carter released 2 different flange gaskets for use on the various YF carburetors when used without a governor.

Carter number 1A-31 was used on:

788, 789, 966, 2100, 2101, 3211, 3379, 3402, 3711, 3770, 3771, 3821, 3946, 3975, 3976, 4043, 4044, 4072, 4073, 4079, 4080, 4085, 4086, 4145, 4202, 4203, 4339, 4367, 4368, 4369, 4370, 4371, 4372, 4373, 4374, 4375, 4376, 4377, 4378, 4387, 4480, and 4492.

Carter 1A-41 was used on:
756, 787, 964, 965, 2008, and 2046.

Note that I did not include the suffix(s) S, SA, SB, etc. If the base number is listed above, the suffix does not matter.

These gaskets should be used directly under the carburetor. If a spacer is used, the reader is responsible for determining the gasket used between the spacer and the intake manifold.

Also, this needs to be said: Carter issued the above listed gaskets for use with UNMOLESTED carburetors. There is always someone that knows more than the engineers and thinks throttle bodies can be traded like baseball cards. Carter made hundreds of different YF carbs, and many additional flange gaskets.

This is a link to pictures of the 1A-31, and 1A-41 gaskets. Note these were removed from original Carter packaging in order to take the picture.

Center to center spacing on the 1A-31 is 2 15/16 inches; while the spacing on the 1A-41 is 2 11/16 inches.

http://www.thecarburetorshop.com/Carter_Chevrolet_YF_flange.jpg

The gaskets released for use with sandwich governors have small round holes instead of the slots.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
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