Impala V8-305 50L VIN H 4-bbl (1982) Transmission - Valve Body Component Information
The difference between the two sets of gaskets is the addition of holes in 1987 to accomodate an auxiliary valve body. Transmissions produced Start of
Production or after the 1987 model year may or may not have an auxiliary valve body, but 1987-89 model years must use gaskets with holes for an
auxiliary valve body even if an auxiliary valve body is not used.
If a 1987 or later transmission does not have an auxiliary valve body - the spacer plate covers up the unused holes in the spacer plate gaskets.
NOTICE:
If the incorrect (1982-1986) gasket set is used on a 1987-89 model year transmission, with or without an auxiliary valve body, the third
clutch exhaust passage will be blocked. This may cause slipping or flaring during a 3-2 shift, a delayed 3-2 downshift, or a burned 3-4
clutch.
SERVICE PARTS INFORMATION:
Model Year
Part # Gasket Set Only
Part # Overhaul Kit
1982-1986
8642993
8649995
1987-1989
8657938
8649995
Parts are currently available from GMSPO.