LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 1991 >> Forward Control 7.4 N >> Repair and Diagnosis >> Engine Performance >> Application >> Engine/VIN Id >> Engine Code Location
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Engine Code Location

The locations of the stamped codes for each particular engine are listed below. Refer to 1990-91 MODEL COVERAGE & IDENTIFICATION .

ENGINE CODE LOCATION

Engine Code Location(s)
LU2, LB4, LO3, LO5 & L19 On front of engine block, on right side above timing gear cover OR on left side of engine block, on engine-to-transmission mating flange.
LN8 & L38 On left side of engine block, at rear below cylinder head OR on left side of engine block, on engine-to-transmission mating flange.
LL2 On front of engine block, on left side above timing gear cover OR on right side of engine block above engine mount.
LH6 & LL4 On front of engine block, right side of timing gear housing casting OR on top of engine block, near left cylinder head-to-engine block mating surface, at front OR on left side of engine block, on engine-to-transmission mating flange.
LG6 On left side of engine block, on engine-to-transmission mating flange.
(1) See ENGINE in BODY, ENGINE, FUEL SYSTEM & IGNITION SYSTEM APPLICATIONS  table for engine code location prefix.