Engines - 1985/1986 Differences/Interchangeability

Number 86-6(Gasoline)-1A Date 10/85
Subject: NEW 1986 3.0L & 3.8L V-6 ENGINES

ALL MODELS EQUIPPED WITH L AND A ENGINES
The 1986 model 3.0L (VIN Code L) and 3.8L (VIN Code A) V-6 engines look very much like the 1985 version, however, changes have been incorporated in the 1986 model that prohibit interchangeability of numerous parts or assemblies between the two units. Some examples of the differences are: block deck height at the cylinder head surface has been lowered .038"; composition head gaskets are used; new torque to yield head bolts; and 5 mm injectors vs. 4 mm for some applications, etc.

Attempts to interchange any of these parts, that are not identified as compatible in the GMWDD Parts Catalog, could create anything from a driveability problem to an inability to reassemble the unit correctly.