V8 Cylinder Head Casting Numbers - 1964 through 1972

These head castings were used in various other models of the Chevrolet lineup such as the passenger car, Chevy II/Nova, Camaro and Corvette. Only Chevelle-specific information is listed here to conserve space. Some casting numbers are NOT listed as they may have been used in other models of the Chevrolet lineup but were NOT used in the Chevelle - such as the 1965 409cid heads #3830817 & #3852583 or 67 Camaro heads #3876775.

The casting number is probably the most significant feature on a cylinder head as it's the hardest to alter. The casting date is usually found near the casting number. Both are found under the valve cover be it a small block V8 (283/307/327/350) or big block Mark IV V8 (396/402/454).

It's important to remember the 'to' and 'from' dates listed may vary due to production lead time and stock inventories being depleted. For example just because a particular head casting may be listed as being used from January to April doesn't imply that the engine assembly plants discarded all pre-January heads or on the 1st of May discard all heads they had in inventory to begin using the newer design.

File photo

File photo

File photo

Courtesy Chris Holcombe
Courtesy Chris Holcombe
Casting clocks. Note the 11 dots plus the number 0 indicating the particular hour of a shift the heads were cast.

Cylinder heads are normally date coded in the form of a letter for the month (see table below), two numbers for the day and a single number for the year.  For example, C259 indicates a date of March 25, 1969.

V8 Cylinder Head Casting Month Codes
A - January B - February C - March D - April
E - May F - June G - July H - August
I - September J - October K - November L - December

Caveats to production dates. Due to inventories, shipping schedules, etc. it is entirely possible that cylinder heads being phased out of production may still appear on Chevelles built after that time.

Head
Number
Year Engine Horsepower Valve Size
Int./Exh.
Combustion
Chamber cc.
Notes
3795896 1964 283
327
195, 220
250
1.72/1.50 59.669 Used in 1964 and 1965.
3782461 1964
1965
1966
327
327
327
300
250, 300
275
1.94/1.50 62.076 Production ended approximately June of 1966 and replaced with #3890462. Casting symbol on exterior face of head is the infamous double-hump design.
File photo
  1964
1965
1966
327
327
327
350
350
350
2.02/1.60 62.076 1966 is late March introduction.
3795896 1965 283 195, 220 1.72/1.50 59.669 Casting symbol on exterior face of head is single centered pyramid on square block.
File photo
3856208 1965 396 375 2.19/1.75 108.989 First square-port Mark IV head. Has spark plug shield boss.
3872702 1966 396 325, 360 2.06/1.72 98.427 All oval-port applications. Has spark plug shield boss. It is debatable as to whether these plug shields were used on the Chevelle but the shields listed in Chevrolet parts books included the Chevelle application.
3873858 1966 396 375 2.19/1.72 108.989 All high performance square-port engine applications. Has spark plug shield boss.
3884520 1966
1967
283
283
195, 220
195
1.72/1.50 60.530  File photo
3890462 1966
1967

1966
1967
327
327

327
327
275
275

350
325
1.94/1.50
1.94/1.50

2.02/1.60
2.02/1.60
62.076
63.305

62.076
63.305
Similar to 3782461. Used from January 1966 through May 1967.
File photo
3904390 1967 396 325, 350 2.06/1.72 98.427 First head without spark plug shield boss. Used until January when replaced with #3909802.
3904391 1967 396 375 2.19/1.72 106.8 Used at least through May 1967 when replaced with #3919840.
File photo
3909802 1967 396 325, 350 2.06/1.72 100.967 January through April of 1967, with redesigned combustion chamber. June 1967 casting dates have been reported for this head.
3911032 1968 307 200 1.72/1.50 69.629 Used in 1968 only. Has temperature sending unit boss.
CHEVELLESTUFF
3917215 1967
1968
396 325, 350 2.06/1.72 100.967 First Mark IV oval-port with temperature sending unit boss, otherwise identical to #3909802. Production from May 1967 to May 1968.
3917291 1967
1968
327 275 1.94/1.50 63.305 Used in late 1967 (May/April) and all 1968. Identical to #3890462 except it has the temperature sending boss. The late 1967 unit has the temperature sending unit boss but is not tapped.
File photo
3917291 1967
1968
327 325 2.02/1.60 63.995 Combustion chamber enlarged and valve guide boss diameter increased to accept the 2.02/1.60 valves.
File photo
3917293 1968 327 250 1.72/1.50 75.340 Low compression, identical to #3884520 except for combustion chamber change and addition of temperature sending boss.
CHEVELLESTUFF
3919840 1967
1968
1969
396 375 2.19/1.72 106.8 First Mark IV to have temperature sending boss. The late 1967 unit has the temperature sending unit boss but is not tapped. Identical to #3904391 except for temperature sending unit boss and two accessory bolt holes added.
File photo
3919842 1969 396 375 (L89) 2.19/1.84 106.8 Aluminum head with temperature sending unit boss, two accessory holes drilled and tapped, revised exhaust manifold surface. Two versions were used during 1968 (non-Chevelle) and 1969. The 1968 and early 1969 version had plugs in both ends of the cylinder head. Approximately June of 1969 one plug was eliminated.
3927185 1969
1970
307 200 1.72/1.50 69.625 Identical to #3884520 except has temperature sending unit boss. Three accessory bolt holes added to each end of the head and combustion chamber revised.
CHEVELLESTUFF CHEVELLESTUFF
3927186 1969
1970
350 300 1.94/1.50 63.305 Similar to #3917291 & #3782461, but with temperature sending unit boss, three accessory holes and casting symbol was smaller.
CHEVELLESTUFF
3931063 1969 396 325, 350 2.06/1.72 100.967 Similar to #3909802 & 3917215 with two accessory bosses above #3 (or #6) exhaust ports for air conditioning rear support bracket. Straight casting flashing.
3932441 1969
1970
350 250, 255
250
1.94/1.50 76.26 Similar to #3927186 with redesigned combustion chamber.
CHEVELLESTUFF
3947041 1969
1970
350 300 1.94/1.50 63.305 Similar to #3782461 with redesigned combustion chamber, addition of a temperature sending unit boss and three accessory holes on end.
CHEVELLESTUFF
3964290 1969
1970
1970
396
402
454
325, 350
330, 350
360
2.06/1.72 100.967 Similar to #3931063 with spark plug seat changed to tapered, "peanut" plug but early castings had standard, "N" reach plug. Straight casting flashing.
3964291 1969

1970
396
427
402
454
375
425
375
450
2.19/1.88 109.037 Similar to #3919840 with spark plug seat changed to tapered, "peanut" plug but early castings had standard, "N" reach plug. Last closed chamber cast iron square-port head. Produced in both plug designs for service replacement of 1965 through 1969 applications.
File photo
3973487 1971
1972
350
350
245, 270
165, 175
1.94/1.50 75.47 Similar to #3832441 & #3782461 with redesigned combustion chamber, addition of temperature sending unit boss, three accessory bolt holes added to end of head, tapered spark plug seat and different external identification symbol cast near the internal casting number.
CHEVELLESTUFF
3973487X 1972 350 165, 175 1.94/1.50 75.47 Used only in late 1972 and overlapped production with #3998993.
CHEVELLESTUFF
3986339 1971 307 200 1.72/1.50 74.56 Similar to #3884520 with redesigned combustion chamber, temperature sending unit boss and tapered spark plug seat.
CHEVELLESTUFF
3993820 1971 402
454
300
365
2.06/1.75 113.060 Cast iron, oval-port and similar to #3931063 with change to open-chamber design, redesigned intake and exhaust valve seats, and tapered spark plugs.
3994026 1971 454  425 2.19/1.88 118.000 Cast iron, square-port with tapered spark plug. Last Mark IV square-port with open chamber design.
3998991 1972 307 130 1.72/1.50 74.56 Similar to #3795896 with tapered spark plug, redesigned combustion chamber, and temperature sending unit boss. First head to use hardened valve seats for unleaded fuel.
CHEVELLESTUFF
3998993 1972
1973
1973
350
307
350
165, 175
115
145, 175
1.94/1.50 75.47 Introduced mid-year (January) to replace #3973487X.
CHEVELLESTUFF
3999241 1972  402
454
240
270
2.06/1.72 113.06 Similar to #3993820 with tapered spark plug seat.
353049 1973 454 245* 2.06/1.72 113.06 Used for all 1973 454 applications.
333882 1974-75
1974
1975
350
400
400
All
150, 180
175
1.94/1.50 75.47 Similar to #3998993 with tapered spark plug seat.
336781 1974
1975
454
454
235
215
2.06/1.72 113.06 Used for all 1974 and early 1975. Replace by #346236 mid-year 1975.
346236 1975 454 215 2.06/1.72 113.06 Replaced #336781 mid-year 1975.

* The 1973 454 Corvette engine was rated at 270hp. Since this head has the same intake/exhaust and cc volume, it's not known why it is listed at 245hp for 1973.

File Photo - 07/08/2009

File Photo - 07/08/2009