Pontiac stamped a variety of codes on the front of the engine block. The first code, located near the passenger side cylinder head, is the motor unit number This number was stamped at the engine assembly plant and it has no correlation to the Vehicle Identification Number. Just below that is the two-digit engine type code. A few inches farther down, near the timing chain cover is a code identifying teh Pontiac division of General Motors, the model year, the vehicle assembly plant, and the last six digits of the VIN number. On the 6 cylinder engines the code is located on the cylinder block below the spark plugs.

Engine Numbers
123456	Motor Unit Number
WC	Engine Type Code
21N 100001	Engine Vin Code
Engine Vin Code:
2	Pontiac Division
1	Model year
N	Assembly Plant
100001	Last six digits VIN

Engine Codes	Cylinders	CID	HP	Comp. Ratio	CARB	Trans
CAA	6	250	145	8.5:1	1 bbl	Manual
CAB	6	250	145	8.5:1	1 bbl	Auto
WC	8	455	335	8.4:1	4 bbl	Manual
WJ	8	455	325	8.2:1	4 bbl	Manual
WK	8	400	300	8.2:1	4 bbl	Manual
WL	8	455	335	8.4:1	4 bbl	Manual
WN	8	350	250	8.0:1	2 bbl
WP	8	350	250	8.0:1	2 bbl
WR	8	350	250	8.0:1	2 bbl	Manual
WS	6	400	265	8.2:1	2 bbl	Manual
WT	6	400	300	8.2:1	4 bbl	Manual
WU	8	350	250	8.0:1	2 bbl	Manual
XR	8	350	250	8.0:1	2 bbl	Auto
XX	8	400	265	8.2:1	2 bbl	Auto
YC	8	455	325	8.2:1	4 bbl	Auto
YE	8	455	335	8.4:1	4 bbl	Auto
YN	8	350	250	8.0:1	2 bbl
YP	8	350	250	8.0:1	2 bbl
YS	8	400	300	8.2:1	4 bbl	Auto
YU	8	350	250	8.0:1	2 bbl	Auto
YX	8	400	265	8.2:1	2 bbl

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This Home Page was created Friday, May 02, 1997
Most recent revision Friday, January, 31th, 2003