The Chevy cylinder head casting codes are one of the best ways to identify a Chevy cylinder head. The code is usually found on the top of the head in between two valves and the rocker arm studs.

Chevy Big Block Cylinder Head Codes (ALL)

Casting No
Years
CID
Intake
Exhaust
Chamber
CC
330864 1970-81 366/427/454 2.06 1.72 Open
330865 1970-84 366/427/454 2.06 1.72 Open
336765 1973-84 427/454 2.06 1.72 Open
336781 1973-85 454 2.06 1.72 Open 113
343771 1968-85 366/427/454 2.06 1.72 Open
343772 1976-84 366/427/454 2.06 1.72 Open
343783 1975-78 454 2.06 1.72 Open
346236 1975-87 454 2.06 1.72 Open 113
346238 1975-87 454 2.06 1.72 Open 113
353049 1970-73 402/454 2.06 1.72 Open 113
473328 1968-85 366 2.06 1.72 Open
3856206 1965-66 396 2.06 1.72 Closed 97.2
3856213 1966-70 366 2.06 1.72 Closed
3872702 1966 396 2.06 1.72 Closed 98.4
3872702 1966 427 2.06 1.72 Closed 98.4
3876875 1966-70 427 2.06 1.72 Closed
3904390 1966-67 396 2.06 1.72 Closed 98.4
3904390 1966-68 427 2.06 1.72 Closed 98.4
3904393 1966-68 366 2.06 1.72 Closed
3909802 1966-67 396 2.06 1.72 Closed 100.9
3909802 1966-68 427 2.06 1.72 Closed 100.9
3917215 1967-69 396 2.06 1.72 Closed 100.9
3917215 1967-70 427 2.06 1.72 Closed 100.9
3917219 1966-70 366/427 2.06 1.72 Closed
3931063 1969-70 396 2.06 1.72 Closed 100.9
3931063 1969-71 427 2.06 1.72 Closed 100.9
3933148 1969 366/396 2.06 1.72 Open 112.1
3933149 1969-70 427 2.06 1.72 Open 122.1
3964280 1966-70 427 2.06 1.72 Closed
3964280 1966-71 454 2.06 1.72 Closed
3964290 1969-70 396/402 2.06 1.72 Closed 100.9
3964290 1969-71 427 2.06 1.72 Closed 100.9
3964290 1969-72 454 2.06 1.72 Closed 100.9
3965198 1969 396 2.06 1.72 Closed
3975950 1968-70 366/427 2.06 1.72 Closed
3986133 1970-85 366/427 2.06 1.72 Closed
3986136 1970-84 366/427 2.06 1.72 Closed
3993820 1971 402 2.06 1.72 Open 113
3993820 1971 454 2.06 1.72 Open 113
3999241 1972 402 2.06 1.72 Open 113
3999241 1972 454 2.06 1.72 Open 113
6272292 1971 402 2.06 1.72 Open
6272292 1971 454 2.06 1.72 Open
10101136 1991-94 454 2.06 1.72 Open
10121033 1978-88 454 2.06 1.72 Open
12352783 1979-93 454 2.06 1.72 Open
14025175 1983-93 454 2.06 1.72 Open
14081044 1986-90 454 2.06 1.72 Open
14092359 1986-89 427 2.06 1.72 Open
14092360 1985-89 454 2.06 1.72 Open
14101398 1986-90 454 2.06 1.72 Open
3856208 1965 396 2.19 1.72 Closed 108.9
3873858 1966-67 396 2.19 1.88 Closed 108.9
3873858 1966-68 427 2.19 1.72 Closed 108.9
3904391 1965-67 396 2.19 1.88 Closed 106.8
3904391 1965-68 427 2.19 1.72 Closed 106.8
3904392 1967 427 2.19 1.72 Closed 106.8
3919840 1967-69 396 2.19 1.72 Closed 106.8
3919840 1967-70 427 2.19 1.88 Closed 106.8
3919842 1968-69 396 2.19 1.88 Closed 106.8
3919842 1968-70 427 2.19 1.84 Closed 106.8
3946074 1969-71 396/402 2.19 1.88 Open 118
3946074 1969-72 454 2.19 1.88 Open 118
3964291 1969-70 396/402 2.19 1.88 Closed 109
3964291 1969-71 427 2.19 1.88 Closed 109
3964291 1969-72 454 2.19 1.88 Closed 108
3964292 1970 454 2.19 1.88 Closed 109
3994025 1971 454 2.19 1.88 Open 118
3994026 1971 454 2.19 1.88 Closed 118
6258723 1971 454 2.19 1.88 Open
6272990 1971-94 454 2.19 1.88 Open 118
10051128 1990-94 454 2.19 1.88 Semi Open
14011077 1989-94 454 2.19 1.88 Open 118
14044861 1989-94 454 2.19 1.88 Open 105
14096188 1987-94 454 2.19 1.88 Open 118
14097088 1989-94 502 2.19 1.88 Open 118
3830817 1965 409 2.06 1.72 Closed
3852583 1963-65 409 2.19 1.72 Closed