RCB 9C-320A

United Motors Service

DIVISION OF GENERAL MOTORS CORPORATION CENTRAL OFFICE —DETROIT

BULLETIN 9 C-320A

PAGE 1

DATE: 7-1-57 File in Front of Chevrolet Bulletin 9 C-320

Rochester Carburetors

PARTS AND SERVICE CHANGE BULLETIN

1957 CHEVROLET—V-8 2GC Carburetor

This service bulletin is to inform you of changes made in production at the factory and give you up-to-date parts and service information to cover these changes.


APPLICATION	GOVERNOR EQUIPPED	POWERGLIDE	SYNCROMESH
CARB. PART NOS.	7010719 Early 7011149 Late	7010648 Early 7011224 Late	7010647 Early 7011131 Late
SERVICE PKGE.	7015719	7015715	7015712
	PART CHANGES


Illus.		Old	New	Old	New	Old	New
No.	Description	Number	Number	Number	Number	Number	Number
20	Fitting, Fuel Inlet	145475	7010976	145745	7010976	145745	7010976
49	Venturi Cluster	7009493	7011497			7009493	7011497
56	Jet-Std.	7002952	7002953	7002952	7002951	7002952	7002953
64	Gasket, Flange		*3718359

Note: The above changes should be made to Bulletin 9 C-320. *New part added for governor equipped models only.

SERVICE CHANGES

The late carburetors listed above were released under the new part numbers due to a new fuel inlet fitting change. Calibrations and adjustments are the same as on the early units.

The venturi cluster was changed on the Governor equipped and Synchromesh carburetors from part No. 7009493 to 7011497. This was a minor production change. No change necessary in servicing earlier units.

Main metering jets were changed on the Governor and Synchromesh carburetors from part No. 7002952 (52) to 7002953 (53).

Main metering jets on the Powerglide carburetors was changed from part No. 7002952 (52) to 7002951 (51). This change was made for improved part throttle performance.

CO, WD, 131, 132:1-9-16, 149, 9X, 9FR, 9FD