1958-1965 Chevrolet engine date codes

Date Codes

Date codes on engines and their parts can help verify if an engine is original to a car. This is especially helpful on cars that do not have a VIN stamped on their engines. Starting in 1962, most high performance engines would be stamped with the cars VIN but this left out all other powerplants and cars built prior to '62. (it wasn't until 1968 that mandatory VIN stamping on all engines was enacted) When a car's VIN matches the VIN stamped on the block, it shows that it's the original engine to the car. (providing it wasn't "restamped" by a forger) This is commonly known as a "numbers matching" car.

In order to be "correct", these date codes have to "pre-date" the cars build date which can be found on the cowl tag by a few days to weeks as the powerplants (as well as transmissions and rear axles assemblies) were prepared ahead of time. (time will vary) By finding a date code that is passed the cars build date ensures that the engine or part is not original to the car.

Date codes can be found cast into most major engine parts such as; block, heads, intake manifolds*, exhaust manifolds, crankshaft, water pump and flywheels. Some parts will have date codes stamped into them such as the engine block assembly date and VIN code, rear axle, alternator, generator, distributor and starter. The transmission and rear axle assembly will also have date codes.

The engine block date code can be found cast into the rear of the block as shown in the pic above. (a bright light and cleaning this area with brake cleaner helps if engine is still in car) One side will have the block casting code and the other will have a date code. This is the date for when the block was casted. There is a date stamped on the front of the block for when it was assembled. For the heads casting date, you'll need to remove the valve cover and look between the stud bosses. (the casting number can also be found here)

*-special note, high performance aluminum intakes may have date codes located under the oil splash heat shield

A few examples of date codes:

A10 - January 1st, 1960
E13 - May 1st, 1963
L224 - December 22nd, 1964
J305 - October, 30th, 1965
A2962 - January, 29th, 1962

See picture above for a sample of this type of date code.

Use this chart to decode them:

Month

A-January
B-February
C-March
D-April
E-May
F-June
G-July
H-August
I-September
J-October
K-November
L-December

Day

1-31

Year

0-1960
1-1961
2-1962
3-1963
4-1964
5-1965

Or: (as shown above)
60-1960
61-1961
62-1962
63-1963
64-1964
65-1965

Occasionally, a Julian Date was used instead of the above. This type consists of only 3 digits. Leap year must be taken into account with this date format to be accurate. For the 1958-65 cars that we are dealing with, only 1960 and 1964 had leap year or an extra day (Feb 29th). Use the appropriate charts below for your year.
A few examples:

A few examples of Julian Date codes below:

070 - March 11th for a non leap year or March 10th with leap year
315 - November 11th for a non leap year or November 10th with leap year
361 - December 26th for a non leap year or December 27th with leap year

Click here to view a sample of a Julian Date Code

Use these charts to decode them:

Julian Date Calender-Non Leap years (1958-1959-1961-1962-1963-1965)
Day	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Day
1	1	32	60	91	121	152	182	213	244	274	305	335	1
2	2	33	61	92	122	153	183	214	245	275	306	336	2
3	3	34	62	93	123	154	184	215	246	276	307	337	3
4	4	35	63	94	124	155	185	216	247	277	308	338	4
5	5	36	64	95	125	156	186	217	248	278	309	339	5
6	6	37	65	96	126	157	187	218	249	279	310	340	6
7	7	38	66	97	127	158	188	219	250	280	311	341	7
8	8	39	67	98	128	159	189	220	251	281	312	342	8
9	9	40	68	99	129	160	190	221	252	282	313	343	9
10	10	41	69	100	130	161	191	222	253	283	314	344	10
11	11	42	70	101	131	162	192	223	254	284	315	345	11
12	12	43	71	102	132	163	193	224	255	285	316	346	12
13	13	44	72	103	133	164	194	225	256	286	317	347	13
14	14	45	73	104	134	165	195	226	257	287	318	348	14
15	15	46	74	105	135	166	196	227	258	288	319	349	15
16	16	47	75	106	136	167	197	228	259	289	320	350	16
17	17	48	76	107	137	168	198	229	260	290	321	351	17
18	18	49	77	108	138	169	199	230	261	291	322	352	18
19	19	50	78	109	139	170	200	231	262	292	323	353	19
20	20	51	79	110	140	171	201	232	263	293	324	354	20
21	21	52	80	111	141	172	202	233	264	294	235	255	21
22	22	53	81	112	142	173	203	234	265	295	326	356	22
23	23	54	82	113	143	174	204	235	266	296	327	357	23
24	24	55	83	114	144	175	205	236	267	297	328	358	24
25	25	56	84	115	145	176	206	237	268	298	329	359	25
26	26	57	85	116	146	177	207	238	269	299	330	360	26
27	27	58	86	117	147	178	208	239	270	300	331	361	27
28	28	59	87	118	148	179	209	240	271	301	332	362	28
29	29		88	119	149	180	210	241	272	302	333	363	29
30	30		89	120	150	181	211	242	273	303	334	364	30
31	31		90		151		212	243		304		365	31

Julian Date Calender-with Leap Years
(1960 & 1964)
Day Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Day
1 1 32 61 92 122 153 183 214 245 275 306 336 1
2 2 33 62 93 123 154 184 215 246 276 307 337 2
3 3 34 63 94 124 155 185 216 247 277 308 338 3
4 4 35 64 95 125 156 186 217 248 278 309 339 4
5 5 36 65 96 126 157 187 218 249 279 310 340 5
6 6 37 66 97 127 158 188 219 250 280 311 341 6
7 7 38 67 98 128 159 189 220 251 281 312 342 7
8 8 39 68 99 129 160 190 221 252 282 313 343 8
9 9 40 69 100 130 161 191 222 253 283 314 344 9
10 10 41 70 101 131 162 192 223 254 284 315 345 10
11 11 42 71 102 132 163 193 224 255 285 316 346 11
12 12 43 72 103 133 164 194 225 256 286 317 347 12
13 13 44 73 104 134 165 195 226 257 287 318 348 13
14 14 45 74 105 135 166 196 227 258 288 319 349 14
15 15 46 75 106 136 167 197 228 259 289 320 350 15
16 16 47 76 107 137 168 198 229 260 290 321 351 16
17 17 48 77 108 138 169 199 230 261 291 322 352 17
18 18 49 78 109 139 170 200 231 262 292 323 353 18
19 19 50 79 110 140 171 201 232 263 293 324 354 19
20 20 51 80 111 141 172 202 233 264 294 325 355 20
21 21 52 81 112 142 173 203 234 265 295 326 356 21
22 22 53 82 113 143 174 204 235 266 296 327 357 22
23 23 54 83 114 144 175 205 236 267 297 328 358 23
24 24 55 84 115 145 176 206 237 268 298 329 359 24
25 25 56 85 116 146 177 207 238 269 299 330 360 25
26 26 57 86 117 147 178 208 239 270 300 331 361 26
27 27 58 87 118 148 179 209 240 271 301 332 362 27
28 28 59 88 119 149 180 210 241 272 302 333 363 28
29 29 60 89 120 150 181 211 242 273 303 334 364 29
30 30 90 121 151 182 212 243 274 304 335 365 30
31 31 91 152 213 244 305 366 31