Engine - Updated Head Gaskets

87chevy18
GMC NUMBER: 88-T-35

GROUP: 6A-Engine Mechanical

DATE: September, 1987

CORPORATE
NUMBER: 866103
SUBJECT: NEW CYLINDER HEAD GASKETS FOR 4.3L, 5.0L AND 5.7L ENGINES

MODELS: 1987 AND PAST MODEL YEAR TRUCKS AND EARLY PRODUCTION 1988 C/K MODEL TRUCKS EQUIPPED WITH 4.3L, 5.0L AND 5.7L ENGINES
An improved cylinder head gasket of composite construction has been released to replace the metal gasket. The new gasket has improved sealing capabilities. The new part numbers shown below should be used for service.

Application Cylinder Head Gasket

4.3L Truck 10066080
5.0L Truck 10066081
5.7L Truck 10066082

Engines manufactured after the following build date codes were built with the new composite gasket.

Engine
Engine Build Date Date Codes

4.3L May 15, 1987 T0515XXX

5.0L July 1, 1987 V0701XXX
K0701XXX

5.7L July 1, 1987 V0701XXX
K0701XXX

FIGURE 1:

Engine date codes aye stamped on a pad at the block to passenger side cylinder head parting line, see Figure No. 1. The built date codes may be found in this area and appear as shown in the following example:

T1202ABC

The first letter indicates the plant where the engine was manufactured, the next four numbers indicate the date of manufacture, in this case, 12th month 2nd day, and the last three digits may be any broadcast code.