Model Year: 1957
Subject: 1957 Corvette Spark Plug Recommendations
Source: Chevrolet Technical Service Bulletin
Bulletin Number: DR #295
Section: VIy
Date: May 22, 1957
TO: ALL CHEVROLET DEALERS
Inasmuch as the grater percentage of Corvette engines are being operated in traffic congested areas AC-46 Spark Plugs are now being installed in production.
AC-46 entered production 4-9-57, Serial number E57S103268.
Corvette Engine Spark Plug Recommendations
| Type | Type Driving | Part No. |
|---|---|---|
| AC-46 | City | 1559494 |
| AC-44 | Town & Country | 1559492 |
| C-43 Comm. | Heavy Duty & High Speed | 5612002 |
| C-42-1 Comm. | Road Racing | 5612140 |
Above information will be inserted in the Corvette Operations Manual and will appear in next edition.
Corvette Engiens with AC 46-5 Plugs
170 Corvettes wewre built during period 3-29 to 4-9-57 with AC 46-5 Plugs installed.
Serial # E57S-103098 to 103268.
These plugs should be changed to AC-46 due to spark plug boots not fitting the AC-46-5 plugs properly.
In cases where units operating in heavy traffic continue to oil foul spark plugs oil shedders should be installed.
ELH:mw
Article ID: 179
Created: July 13, 2014
Last Updated: July 13, 2014
Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article/1957-corvette-service-bulletin-spark-plug-replacement-179.html