Jeep CJ Numbers
All of this information has been compiled from other sources. I've tried to give credit where it is due, but this data is so sparse, I wanted to put it all in one place. Happy hunting...

Engine Day Build Code (Engine Serial Number / Production Number)
Source page for this data: amcrc.com
Where do I find my build code?

AMC Serial Number locations
OVER/UNDER SIZE CODE

UP TO MID 1967: Some engines will have a second three letter code under or beside the serial number or Day Build Code. This code is used to indicate under and/or over size parts. All three letters will be present if any part was factory altered from original specifications. If .010 inch over or under would not correct the fit of the part(s), they were replaced. No engine was fitted from the factory with parts that were over .010 inch above or below standard. The code represented the bore (1st letter), main bearings (2nd letter), and rod bearings (3rd letter). In any position, an "A" indicates standard size, "B" .010 inch undersize, and "C" .010 inch oversize. The code is located directly below the serial number or Engine Day Build Code on 172-195.6 six cylinder engines, on the boss directly above the oil filter on 199-258 six cylinder and AMC built four cylinder engines, and on the valve cover tag on V8 engines. MID 1967 AND LATER: A different letter represents each part and the modification. The letter is located on the boss directly above the oil filter on six cylinder engines, on the valve cover tag on V8 engines. One or more letters may be present: B- 0.010" oversize cylinder bore
C- 0.010" oversize camshaft bearing bore
M- 0.010" undersize connecting main bearings
P- 0.010" undersize connecting connecting rod bearings

ENGINE DAY BUILD CODE

AMC used a the "Engine Day Build Code" as a serial number for all engines starting in 1960. This code gives the date the engine left the assembly plant fully running and has a code for the engine size/type.

NOTE: This code is NOT necessarily the same as found on the VIN. In some cases it is, but often the VIN code changed whereas the build code remained for any size engine.

An important thing to remember about AMC engines is that changes were made on a calendar year basis, not model year. The engine plant ran on its own schedule! This is why some 1980 model vehicles have the "heavy" 258 and others the "light" 258 -- changes were made early in calendar year 1980.

The Engine Day Build Code consists of six characters:

1. Year built code 2 & 3. Number of the month 4. Engine size/type code 5 & 6. Day built

Thus, "409C21" indicates 1962, September, 195.6 OHV (cast iron), 21st day. The only way to determine the year is 1962 instead of 1971, 1984, or 1992 is to know that the 195.6 OHV engine was discontinued after 1965, and what a 195.6 looks like (very different than the 199/232/258). Most codes do not overlap very much. For those that do (such as 3 -- 1961, 1970, 1979, 1983, 1993) casting numbers may have to be consulted if the engine date is important, such as for a restoration.

Day Built "Year Codes"
1=1959 2-1960 3=1961 4=1962 5=1963
6=1964 7=1965 8=1966 9=1967 1=1968
2=1969 3=1970 4=1971 5=1972 6=1973
7=1974 8=1975 9=1976 1=1977 2=1978
3=1979
Beginning in 1980 the last digit of the year is used (1980=0, 1981= 1, etc.)

Engine Size/Type Codes

1960-1967: AMC complicated things these years by using a different code in the VIN of each model for the same engine in at least 66 and 67. This confuses many sources! The codes below are used in the Engine Day Build Code, which is the same for all models. Serial number codes will be found with serial number decoding information. Years following code is the years the engines were available.

A- 195.6 1 bbl (60-65, L-head)
A- 199 1 bbl (66-67)
B- 195.6 (61-64, OHV aluminum, 1 or 2 bbl)
C- 195.6 OHV (61-65, OHV iron, 1 or 2 bbl)
D- 250 (60-61, 2 or 4 bbl)
E- 327 2 bbl (60-66)
F- 327 4 bbl (60-66)
G- 287 2 bbl (63-66)
H- 290 2 bbl (66-67)
J- 199 1 bbl (66-67)
L- 232 (64-67, 1 or 2 bbl)
N- 290 4 bbl (66-67)
Z- 343 4 bbl (67)

1968-2001: Someone at AMC decided to simplify things, or maybe the U.S. Government decided for them since engines now had to be qualified for emissions by type and size? In any case, all models used the same codes for the same engines.

Some codes were used for more than one engine. Year ranges are given for code use.

VIN and engine code numbers are different! This can be confusing. The 4.0 has an engine code of MX, but there are three different VIN codes (M, L, S). The earliest VIN code usually matches the engine code, later versions of the same engine may have different VIN codes but engine code usually remains the same.

A- 199 1 bbl (70)
A- 258 1 bbl (71-79)
B- 258 1 bbl Low Compression (71-74, Jeep ONLY)
B- 151 2 bbl (80-83, GM 2.5L)
B- 126 Diesel (85-87, Renault 2.1L, Jeep XJ ONLY)
C- 258 2 bbl (4.2L, 76-89)
E- 232 1 bbl (70-79)
F- 232 1 bbl Low Compression (71-74, Jeep ONLY)
F- 145 Diesel (81-86, Jeep ONLY)
G- 232 2 bbl (70-74)
G- 121 2 bbl (77-79)
H- 290 2 bbl (68-69)
H- 304 2 bbl (70-79)
J- 199 1 bbl (68-69)
L- 232 1 or 2 bbl (68-69)
M- 304 2 bbl Low Compression (71-74, Jeep ONLY)
MX- 242 MPI (4.0L MPFI, 86-01, Jeep ONLY)
N- 290 4 bbl (68-69)
N- 360 2 bbl (5.9L, 70-91)
P- 360 4 bbl (70-77)
R- 134 1 bbl (70, F-head, Jeep ONLY)
S- 343 2 bbl (68-69)
T- 134 1 bbl Low Compression (70, F-head, Jeep ONLY)
U- 150 (84-01, AMC 2.5L, Jeep & Eagle ONLY)
W- 390 4 bbl (68-69)
W- 173 2 bbl (84-86, GM 2.8L V6, Jeep XJ ONLY)
X- 390 (70)
Y- 390 (70 Machine)
Y- 318 MPI (93-96, Chrysler 5.2L, Jeep Grand Cherokee ONLY)
Z- 343 4 bbl (68-69)
Z- 401 (71-77)

For more information on AMC cars check the "American Independent Magazine" website: http://home.att.net/~farna . An "AMC Annual" is published yearly listing all known AMC and related makes clubs. There may be one in your area! The AMC Annual may be purchased without subscribing.

The very best thing you can do for your AMC is join a local club. If there are no local clubs, you should still consider joining one of the national clubs. AIM offers information and some support for ALL AMC vehicles, the clubs tend to gravitate toward specific interests and offer some support, such as holding meets at many locations across the country, that AIM can't. Even if you do join a local club, you may be interested in services from one or more of the national clubs as well. But if you are a genuine "AMC nut", subscribe to AIM to get a REAL fix!

Frank Swygert -- Gulfport, MS
Publisher, "American Independent Magazine" (AIM)
Supporting all AMC related vehicles, 1902-1987
Website: http://home.att.net/~farna

Return to Top

Jeep Block Casting Numbers
Source page for the data in this table
MAKE AND YEAR
C.I.D. LITRE BORE CYL. DESCRIPTION
BLOCK CASTING NUMBER
HEAD CASTING NUMBER
CRANK CASTING NUMBER
AMC
1983-88
150 2.5 3.875 L-4 Eagle, 7/16"
3239448
3244893
3239611
AMC
1988-71
150 2.5 3.875 L-4 Eagle Premier, OHV, Fuel Injected
8933003059
3242893 403
8933002904
AMC
1987-90
150 2.5 3.875 L-4 Fuel Inj., 2.06" Crank Neck, 7/16" Head Bolts, Wrangler
8933004200
408
8933002904
AMC
1986-90
150 2.5 3.875 L-4 Carb., 1/2" Head Bolts, 2.06" Crank Neck, Wrangler
53005532
.
8933002904
AMC
1991-92
150 2.5 3.875 L-4 Fuel Injected, 7/16" Head Bolts, Wrangler
63008403
117
8933002904
AMC
1970-72
232 3.8 3.75 L-6 W/Rocker Shaft, Spec. Flat Back or Flanged Style Crank
3199962
3218618
3189886
3170717
3211040
3172216
3172218
3188947
3204904
AMC
1972-74
232 3.8 3.75 L-6 W/Rocker Shaft, Spec. Flat Back or Flanged Style Crank
3213867
3218618
3222380
3710717
3189886
3211040
3213809
3224490
3214722
AMC
1975-79
232 3.8 3.75 L-6
3224098
3227445
3227258
3241722
AMC
1987-90
241 4.0 3.875 L-6
53005535
8933002665
2686
3003453
AMC
1991-93
241 4.0 3.875 L-6
53008405
7120
3003453
AMC
1970-72
258 4.2 3.75 L-6 W/Rocker Shaft, Spec. Flat Back or Flanged Style Crank
3199962
3211040
3170717
3189886
3199798
RD67703
AMC
1970-72
258 4.2 3.75 L-6 W/Rocker Shaft
3218618
3222380
3213867
3211040
3170717
3214723
AMC
1975-79
258 4.2 3.75 L-6 Spec. Location of Temp. Send. Unit, 1/2" Head Bolts
3227445
3224098
3227258
3214723
AMC
1980
258 4.2 3.75 L-6 Temp. Send. Unit at Top Rear of Head
3235077
3227258
3214723
AMC
1981-85
258 4.2 3.75 L-6 7/16" Head Bolts
3235444
3933000
3224480
3241656
3235477
AMC
1986
258 4.2 3.75 L-6 1/2" Head Bolts
3235444
3933002
3235477
AMC
1987-89
258 4.2 3.75 L-6 2.06" Crank Neck, Spec. if Alum. or Plastic Valve Cover, 1/2" Head Bolts
3235444
3661
3727
AMC
1970-79
304 5.0 3.75 V-8
3195527
3212990
3218086
3233324
RD51261
4487237
3195292
3214724
AMC
1970-78
360 5.9 4.08 V-8 Spec. Stud Type or Bolt Down Rocker Cyl. Heads. Must Have Head Cast #
3195528
3196291
3220502
3231475
3216090
3219993
3233344
RD51261
4487237
3195292
3214724
3214754
AMC
1971-76
401 6.6 4.165 V-8 Spec. Stud Type or Bolt Down Rocker Cyl. Heads. Must Have Head Cast #
3198951
3196291
3219993
3216090
3220502
3231475
3190079
3196921
3214725
3220411
3199842

Return to Top

Return to Index
Hosting by WebRing.