Engines

AMC V-8 Oiling Upgrade (Adobe Acrobat file 2.58 MB)

Engine Number Information

The engine number is located on a pad behind the water pump on 134-ci fours and on a pad on the block deck visible between the first two exhaust manifold runners on the passenger side. Four- cylinder engines to 1967 will begin with a "4J" followed by a six digit sequential serial number. After 1967, both F-134 and V-6 engines share the following codes:

1st Digit	2nd Digit	3rd Digit	4th Thru 6th Digits
Market	Year	Engine	Build Date
M:Military	L:1965 V-6	F:F-134
E:Export	M:1966 V-6	H:V-6, 9.0 CR, 2 bbl
D:Domestic	N:1967 V-6	K:V-6, 7.6 CR
	P:1968 V-6
	R:1969 F-134 & V-6
	S:1970 F-134 & V-6
	T:1971 F-134 & V-6

7th & 8th Digits*	9th Digit*	10th & 11th Digits**
Internal Dimensions	Type	F-134 Compression Ratio
A:.010 undersize crank & rod bearings	S:service engine	60:6.0:1
B:.010 oversize bore	R:short block	63:6.3:1
M:.010 undersize mains(F-134 only)		67:6.7:1
P:.010 undersize rod bearings(F-134 only)		71:7.1:1
AB:.010 undersize main & rod bearings

* These digits only in evidence if there is an applicable change to standard spec.

** Applies to F-134 only

The 1972-1986 six-cylinder engine numbers are located on a boss near the front of the block on the distributor side, just below the head. V-8 engines have the engine numbers stamped on a tag that is riveted to the right (oil filter) valve cover. Also, the engine block will have a cast-in "304" on the sides of the block. The 1980-1983 GM-built four has an engine number that is indecipherable. The AMC 151 from 1983 to 1986 has a number on the front right upper part of the block.

1st Digit	2nd & 3rd Digits	4th Digit	5th Digit
Year	Month Built	Type	Day Built
5:1972		A:258 ci, 1-bbl 8.0:1 cr
6:1973		B:258 ci,1-bbl 7.6:1 cr('72-'79)
7:1974		B:151 ci, 2-bbl('80-'86)>
8:1975		C:232 ci, 1-bbl 8.0:1 cr('72-'74)
9:1976		C:258 ci, 2-bbl ('75-'86)
1:1977		D:232 ci, 1-bbl 7.5:1 cr
2:1978		H:304 ci, V-8, 2-bbl 8.4:1 cr
3:1979		N:360 ci, V-8 2-bbl
0:1980		P:360 ci, V-8 4-bbl
1:1981		Z:401 ci, V-8 4-bbl
2:1982
3:1983
4:1984
5:1985
6:1986