Small Block Chevy Head Casting Numbers Post link: https://angf35eis.com/sbc-head-casting-numbers/

1. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
176450 75-76 262 - 305 1.71 / 1.5
330545 73 350 2.02/1.60 76cc
330862 71-73 400 1.94/1.50
330864 70-81 366/427/454 2.06/1.77 Open chamber Oval port
330865 70-84 366/427/454 2.06/1.77 Open chamber Oval port
330866 68-78 366/427 Oval Port Open chamber
330867 68-73 427 Oval Port Open chamber
333881 74-75 350 2.02/1.60 76cc
333882 74-80 350/400 76cc
336768 73-76 427 Oval Port Open chamber
336781 73-85 454 2.06/1.77 113cc Oval port
340292 70's 64cc angle plug, over the counter
343771 68-85 366/427/454 2.06/1.77 Open chamber Oval port
343772 76-84 366/427/454 2.06/1.77 Open chamber Oval port
343783 75-78 454 2.06/1.77 Open chamber Oval port
346236 75-87 454 2.06/1.77 113cc Oval port
346238 75-87 454 2.06/1.77 113cc Oval port
352625 70-76 454 Oval Port Open chamber
353049 70-73 454 2.06/1.77 113cc Oval port
354434 75-79 262/267/305 60cc
358741 76-79 305
359944 71-79 350 1.94/1.50 76cc
366765 73-84 427/454 2.06/1.77 Open chamber Oval port
367450 75-76 262
376445 77-85 350 76cc
376450 75-81 262/267/305 60cc 6 or 7 exhaust bolt holes

2. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
376455 77-85 350
376495 Jun-79 350 1.94/1.50 76cc
383882 71-73 400
399380 70-73 400 76cc
426424 72-82 305/350/400 1.72/1.50
458624 69-84 350 1.94/1.50 76cc
458642 75-84 350
460703 78-80 350 1.94/1.50 76cc
462614 77-79 305 60cc
462624 75-86 350/400
1.72/1.50;
194/1.50;
2.02/1.60 76cc
464033 76-86 350 1.94/1.50 76cc
464036 76-86 350 1.94/1.50 76cc
468642 76-up 350/400
471513 79 267/350
472424 76-79 305 1.72/1.50
473328 68-85 366 2.06/1.77 Open chamber Oval port
474213 78-82 305 1.72/1.50
474214 78-82 350 1.94/1.50 76cc
475590 78-82 400 1.94/1.50 76cc
517513 79 267/350
1816887 63 283 Made in "Canada" GMC Truck
3030817 74 400 2-bolt
3238882 68-69 350 1.94/1.50 76cc
3297185 57-67 307/327/350 1.72/1.50
3391635 68-76 305

3. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3636839 55 265
3703523 55 265 1.72/1.50 195HP
3703524 55 265
3713358 55-56 265
3713569 55-56 265
3720991 56-57 265
3725306 56 265
3727185 69-73 307
3731262 56 265 1.72/1.50 Dual Quad Corvette
3731539 57 283 283 HP FI
3731544 57-61 283
3731548 57-62 283
3731554 57-62 283
3731556 57 283 Made in "Canada" Truck
3731762 56 265 Vette 2x4 Carbs
3732791 58 348
3737465 60-61 283
3737739 57-62 283 283 and 283 Corvette F.I.
3737775 62-67 283/327
3740997 57 283 1.72/1.50 Dual Quad FI & 4-brl 220-270HP
3743056 58 283
3743096 62-67 327 GMC Truck
3747363 57-61 283
3747460 59-67 283/327 70cc
3748056 62-67 327 1.72/1.50
3748720 57-58 283 1.72/1.50 Dual Quad FI & 4-brl Corvette

4. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3748770 58 283
3748772 58-61 283
3755537 57-62 283
3755538 59 283 1.72/1.50 250-290HP FI Corvette
3755539 58-62 283
3755549 57-62 283
3755550 59 283
3755585 62-67 327 GMC Truck
3755896 62-64 283 1.72/1.50
3756519 57-62 283 283 and 283 Corvette F.I.
3758379 59-61 348
3759256 58 348
3760116 59 283 1.72/1.50 Dual Quad FI & 4-brl Corvette
3767460 59-60 283
3767462 62-67 327
3767465 59-61 283
3767738 59-61 348
3767754 59-61 283 60cc
3767792 60-64 283
3770126 67-70 327/350 1.94/1.50
3773012 55 265 1.72/1.50
3774634 64-67 327 1.72/1.50
3774682 60-64 283/327 70cc
3774684 62-64 327 75cc
3774690 58 283 1.72/1.50 FI Corvette
3774692 58-64 283 60cc

5. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3776434 64-67 327
3781147 60-61 348 High Perf
3782461 64-66 327 62cc Camel hump, no accessory holes, 160/62cc port volumes
3782462 67 327 1.94/1.50 Corvette 2.02/1.60
3782870 62-67 327 327 and 327 Corvette
3782879 62-67 327 327 and 327 Corvette
3789817 62-67 327 327 and 327 Corvette
3789935 57-62 283
3790721 64-67 283
3792563 65-67 327
3795586 61 409 360HP
3795893 58-72 283 - 307 - 327
3795896 63-65 283 60cc
3796896 64-67 283 1.72/1.50 60cc 60cc Chevy II
3798996 63-67 327
3814462 67 350 1.94/1.50
3814480 60-67 283/327 1.72/1.50 70cc
3814482 62-67 283/327/350 75cc
3814690 62-64 409 High Perf
3817680 63-67 283/327
3817681 62-67 327
3817682 61-62 283
3819333 62-65 348/409
3830817 63-65 409 340HP
3836839 55 265
3836842 57-67 283/327

6. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3836924 63-64 283 1.72/1.50
3836942 58-62 283 1.72/1.50
3837063 58-62 283 1.72/1.50
3837064 56-62 265/283
3837065 55-56 265 Truck
3837731 63 409 High Perf Z-11
3837739 57 283 283 and 283 truck
3837775 62-67 283/327 1.72/1.50
3848720 57-58 283
3849820 65 327 1.72/1.50
3849852 57-67 283
3849935 65-67 283
3852172 62-64 327
3852583 65 409 400HP
3854520 62-67 283/327 1.72/1.50
3855961 68-76 350 2-bolt
3856206 65-66 396 2.06/1.77 98cc 98cc Oval port
3856208 65 396 2.06/1.77 109cc 109cc Z-16/L-37 Rectangular port
3856213 66-70 366 2.06/1.77 Closed chamber Oval port
3856260 68 396 Oval Port Closed chamber
3858174 65-67 327
3864812 57-67 283 283 and 283 truck
3867802 57-60 283 1.72/1.50 FI Corvette
3872702 66 396/427 2.06/1.77 98cc 98cc Oval port L-34/L-35/L-36
3873064 56-57 265 1.72/1.50
3873858 66-67 396/427 2.06/1.77 109cc 109cc L-78/L-72 Rectangular port

7. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3876132 62-67 327 327 and 327 Corvette
3876487 71-73 350 1.94/1.50 76cc
3876775 60-67 283/327 75cc
3876875 66-70 427 2.06/1.77 Closed chamber Oval port
3878775 64-67 327 1.72/1.50
3884520 60-67 283 60cc Some marked "Made in Canada", also used by Studebaker
3890462 66-67 302/327/350 64cc Camel hump, no accessory holes
3891462 62-67 302/327/350 1.94/1.50 2.02/1.60 64cc
3891492 64-67 327 1.94/1.50
3892657 65-67 327
3896944 65-67 283
3901068 87-up 350 64cc Crate motor, 285HP
3904390 66-67 396/427 2.06/1.77 98cc 98cc Oval port L-34/L-35/L-36
3904391 65-67 396/427 2.06/1.77 107cc 107cc L-78/L-71/L-72 Rectangular port
3904392 67 427 2.19/1.88 106cc 106cc L-88/L-89 Aluminum Rectangular port
3904393 66-68 366 2.06/1.77 Closed chamber Oval port
3908952 67 427 Oval Port Open chamber
3909802 66-67 396/427 2.06/1.77 100cc 100cc Oval port L-34/L-35/L-36/L-68
3911011 68 327
3911032 68 307/327 70cc
3912264 58-62 283
3912265 63-64 283
3912291 68-70 302/327/350 1.94/1.50 2.02/1.60 64cc Doubble humps
3912311 65-67 327
3912313 65-67 327
3914636 68-73 307

8. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3914660 68-69 327 327 and 327 Corvette
3914678 68-69 327 327 and 327 Corvette
3917215 67-69 396/427 2.06/1.77 100cc 100cc Oval port L-34/L-35
3917219 66-70 366/427 2.06/1.77 Closed chamber Oval port
3917264 67 302 2.02/1.60 64cc 64cc Z-28
3917290 67-68 307/327
3917291 67-68 302/327/350 64cc Camel hump, no accessory holes
3917292 68 327/350 64cc Camel hump
3917293 67-68 307/327 75cc
3919840 67-69 396/427 2.06/1.77 107cc L-78/L-71/L-72 Rectangular port
3919842 68-69 396/427 2.19/1.88 106cc L-88/L-89 Aluminum Rectangular port
3921175 66 327 1.94/1.50
3923441 67-76 350 1.94/1.50 76cc
3927185 69-76 307/327/350 70cc
3927186 69-70 302/350 64cc Camel hump, has accessory holes
3927187 69-70 350 64cc Camel hump, has accessory holes
3927188 69 327 74cc
3928454 68 307 1.72/1.50
3928455 68 302/327 2.02/1.60 64cc 325 & 350HP
3928494 68 327 2.02/1.60 64cc 350HP 4-brl
3928495 68 327 1.72/1.50
3931063 69-70 396/427 2.06/1.77 100cc Oval port L-34/L-35
3931633 68-73 307
3931635 68-76 350
3931637 68-69 327
3931638 68 327 Truck

9. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3931639 68 302 2.02/1.60 64cc
3932373 68-73 307
3932386 68-76 327 - 350 350 4-bolt and 327 Corvette
3932388 68-76 350 2-bolt
3932441 69-70 350 76cc
3932454 69-73 307
3932882 76 400
3933148 68-73 350 76cc
3933149 69-70 427 2.06/1.77 122cc Oval port
3935401 68-76 427 Oval Port Open chamber
3941174 68 327 1.72/1.50
3946074 69-71 396/454 2.19/1.88 118cc L-88/ZL-1 Aluminum Rectangular port
3946812 69 350
3946813 69-79 350 Truck
3947014 68-70 350
3947040 68 327 64cc Right angle casting identifier, good HP head, used in trucks, no accessory
3947041 69-70 302/350 64cc Right angle casting identifier, accessory holes, good HP head
3951509 74 400 2-bolt
3951511 70-73 400 4-bolt
3951598 70 400 76cc
3956618 68-76 350 4-bolt
3958618 68-76 350 2-bolt
3961598 70-76 400 1.94/1.50 76cc
3964280 66-70 427/454 2.06/1.77 Closed chamber Oval port
3964286 350
3964290 69-70 396/402/427/454 2.06/1.77 100cc Oval port

10. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3964291 69-70 396/402/427/454 2.19/1.88 108cc L-78/L-71/L-72/LS-6 Rectangular port 325cc intake
3964292 70 454 2.19/1.88 109cc LS-6 Rectangular port
3965198 69 396 2.06/1.77 Open chamber Oval port
3965742 70 350 over the counter, angle plug L98 style
3970010 68-76 350 4-bolt
3970020 68-73 307
3970126 67-71 327/350
3970721 64-67 283
3971293 68-69 307 - 327
3973195 71-73 400 1.94/1.50 76cc
3973370 69-70 350 64cc over the counter in US, Canadian 350/300hp production use in Pontiac, s
3973414 70 350 64cc Camel Hump, LT1-350/370hp
3973487 71-72 350
1.94/1.5;
2.02/1.6 75cc
was also used on '71 350/330hp LT1
3973493 71-72 400 76cc
3975950 68-70 366/427 2.06/1.77 Closed chamber Oval port
3981462 62-67 302-327-350
3986133 70-85 366/427 2.06/1.77 Closed chamber Oval port
3986136 70-84 366/427 2.06/1.77 Closed chamber Oval port
3986316 71 350 76cc
3986330 69-79 350 1.94/1.50 76cc
3986336 71 350 76cc
3986339 71 307/350 74cc
3986388 68-76 307/350
3990941 68-82 307/350
3991492 70 350 64cc LT1, Camel hump, accessory holes, straight plug
3993820 71 402/454 2.06/1.77 113cc Oval port

11. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
3994025 71 454 2.19/1.88 118cc LS-6 Rectangular port
3994026 71 454 2.19/1.88 118cc LS-6 Rectangular port
3997417 71 307 1.72/1.50
3998916 72 350 76cc also used w/'72 350 LT1, big valve, screw in studs
3998920 72-73 350
3998991 72-73 307/350 75cc
3998993 72-73 307/350 75cc
3998997 72-73 350/400 76cc chambers
3999241 72 402/454 2.06/1.77 113cc 113cc Oval port
4079261 75 350
6258723 71 454 2.19/1.88 118cc LS-6 Rectangular port
6259425 68-76 350 2-bolt
6259515 73 350
6260855 73-75 350 1.94/1.50 76cc
6260856 73-76 350 1.94/1.50 76cc
6272070 73 350
6272292 71 402/454 2.06/1.77 Open chamber Oval port
6272990 71-94 454 2.19/1.88 118cc Replacement Rectangular port 325cc intake
10033867 62cc Aluminum, over the counter Pontiac 23' head, angle plug, 196cc intake po
10045427 Pontiac/Chevy Aluminum, 91cc chamber Large Rectangle Port
10045434 55cc Aluminum, Over the counter Pontiac 15' head, angle plug, raised runner,
10049875 Pontiac/Chevy Aluminum Small Rectangle port
10051101 55cc Aluminum, Bowtie, angle plug, raised runner, 196cc intake port
10051128 90-94 454 2.19/1.88 72cc Bowtie Aluminum Rectangular port 400cc intake
10052902 427 Oval Port Open chamber
10065202 87-95 350 Truck

12. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
10065203 87-95 350 Truck
10065204 87-95 350
10065205 87-95 305
10065206 87-95 350
10065207 87-95 305
10088113 88-up 350 194/1.50 58cc Aluminum, angle plug, raised "D" port exhaust
10093328 61cc Aluminum, Over the counter Pontiac 15' head, 224cc ports, "roll over" hea
10101136 91-94 454 2.06/1.77 Open chamber Oval port
10101140 91-01 366/427 Oval Port Closed chamber
10106178 90 350 Aluminum, LT5, ZR1, DOHC, 32-Valve, pass. Side.
10106179 90 350 Aluminum, LT5, ZR1, DOHC, 32-Valve, drivers Side.
10110810 91-up 350 65cc Gen. 1
10114156 91-01 454 Oval Port Open chamber
10120928 87-95 350
10121033 78-88 454 2.06/1.77 Open chamber Oval port
10125320 94-96 350 Gen.II LT1, cast iron version, used on "9C1" Police package, Impala SS,
10128374 92-up 350 53cc Aluminum, Gen.II LT1, angle plug, reverse flow cooling, 175/68cc ports
10134352 Bowtie 45cc Aluminum, angle plug, "low" port, 223cc intake port, 18' race head
10134363 Bowtie
This casting # has been used
in many different versions of this
aluminum 18' and 15' Bowtie race head.
Different chamber volumes, port
volumes, port locations, valve sizes,
etc. were used. Check this casting
carefully to determine which features
it may have. There are at least 6
different versions as of 11/99
10141279 96-01 454 100cc Vortec 7400 chambers Oval Port
10147898 95-98 350 Gen.I crate motor

13. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
10159550 87-95 350
10159551 87-95 305
10159552 87-95 350
10159553 87-95 305
10174389 91-94 350 Aluminum, LT5, ZR1, DOHC, 32-Valve, pass. Side.
10174390 91-95 350 Aluminum, LT5, ZR1, DOHC, 32-Valve, drivers Side.
10185040 Bowtie 45cc Aluminum, Bowtie, 1st version, symmetrical ports, 263cc intake ports, spl
10205245 93 350 68cc Aluminum, Gen.II LT1, reverse flow cooling, 175/68cc port volumes
10207643 94-96 350 68cc Aluminum, Gen.II LT1, reverse flow cooling, 175/68cc port volumes
10208890 94-96 265 Gen.II, L99, 4.3 Liter V8, cast iron, reverse flow cooling
10215339 97 350 68cc Aluminum, Gen.III, LS1,
10225121 94-95 350 Aluminum, LT5, ZR1, DOHC, 32-Valve, Drivers Side.
10225122 95 350 Aluminum, LT5, ZR1, DOHC, 32-Valve, Pass. Side.
10239902 96-up 350 54.4cc Aluminum, Gen.II LT4, reverse flow cooling, 195cc Intake port, angle plug
10239906 96-up 350 1.94/1.50 Vortec 5700, "L31", 170cc Intake port
10487052 77-90 366 Oval Port Open chamber
12352783 79-93 454 2.06/1.77 Open chamber Oval port
12363391 Oval Port Bowtie Aluminum Signature Series
12363401 Rectangle Port Bowtie Aluminum Signature Series
12367712 99-up 2.00/1.55 62cc Aluminum, FastBurn, 210cc Intake port
12367713 99-up 2.00/1.55 62cc Aluminum, Fast Burn used on ZZ430 crate motor, 210cc Intake Port
12480005 2000 2.125/1.625 38cc Aluminum, Ls1"GTZ", angle plug,
12480011 97-up 48cc Aluminum, "SB2.2" 2nd version, "mirror ports" revised valve angles and p
12480034 2.02/1.60 64cc Bowtie Phase III Angle plug 184 cc intake runner
12506450 87-95 350
12509859 87-94 305

14. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
12516852 87-95 350
12529742 95-96 265 Gen.II, L99, cast iron
12551561 96 350 Aluminum, Gen.II, "LT1"
12552520 97-up 305 Vortec, truck
12554290 94-96 350 Gen.II LT1, cast iron version, used on "9C1" Police package, Impala SS,
12554291 95-96 265 Gen.II, "l99" CAST IRON
12555690 96 350 Aluminum, Gen.II, "LT4"
12556743 99 325 Aluminum, Gen.III, 5.3L truck, van
12558059 97 305 1.84/1.50 Vortec, truck
12558062 98 350 1.94/1.50 68cc L31 Vortec, 170cc Intake port, truck
12558162 01 & UP 496 Gen.VII Vortec 8100 8.1L truck
12558806 97-98 350 68cc Aluminum, Gen.III, "LS1"
12559853 99-up 350 68cc Aluminum, Gen.III, "LS1"
12559862 99-00 Aluminum, GEN.III, 4.8/5.3L
12559895 00-up 325 Aluminum, Gen.III, Vortec, 5.3L
12560241 98-01 454 Vortec 7400 100cc chambers Oval Port
12561706 44565 Aluminum, Gen.III, 5.3L
12561873 99-01 364 71cc Iron, Gen.III
12562317 44565 364 71cc Aluminum, Gen.III
12562932 91-95 454/502 Oval Port truck crate motor 118cc chambers
12562934 00 & UP 502 GenVI Marine
12564241 00-up 350 68cc Aluminum, Gen.III, "LS1"
12564243 01-up 350/364 Aluminum, Gen.III, "LS6", "LS2"
12572035 44565 364 71cc Aluminum, Gen.III, 6.0L
14008856 79-81 267
14010201 82-85 305

15. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
14010516 80-86 350
14011034 Bowtie 64cc Iron, 184cc intake ports, angle plug, "Phase II head"
14011049 Bowtie 55cc Aluminum, 180cc intake port, angle plug, "Phase 6"
14011077 89-94 454 2.19/1.88 118cc Replacement Aluminum Rectangular port 295cc intake
14011083 55-86 350 1.94/1.50 64cc Crate motor for years indicated. 285/300HP
14014415 80-85 267/305
14014416 80-86 305 1.84/1.50 58cc
14014440 80 305 1.84/1.50
14019821 80-86 350
14019924 79-81 267
14019926 80-86 350
14020516 80-86 305/350 1.84/1.50
14020517 80 350
14020555 81 305
14020556 81 350
14022056 85 350
14022206 80 350
14022301 80-86 305
14022601 80-86 267/305
1.72/1.50;
1.84/1.50 53cc
14022801 80-86 305
14024816 350 1.94/1.50 76cc Gen.I crate motors
14025175 83-93 454 2.06/1.77 Open chamber Oval port
14034806 78-82 267
14034807 78-86 305
14034808 80-86 350
14034810 80-86 350 Truck

16. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
14034811 80-86 350 Truck
14039121 81-86 305 Truck
14039122 81-86 305 Truck
14044861 89-94 454 2.19/1.88 106cc Bowtie Aluminum Rectangular port 380cc intake
14071114 80-86 350
14075381 80-86 350 Truck
14079261 86 350
14081044 86-90 454 2.06/1.77 Open chamber Oval port
14081045 78-87 454 Oval Port Open chamber
14081052 85-87 366/427/454 Oval Port Open chamber
14085844 80-86 350 Truck
14085963 86 350
14088526 350 Aluminum, Gen.II, LT1
14089119 86-88 350
14092359 86-89 427 2.06/1.77 Open chamber Oval port
14092360 85-89 454 2.06/1.77 Open chamber Oval port
14094093 86-88 350
14096188 87-94 454 2.19/1.88 118cc Replacement Rectangular port 325cc intake
14096217 55-86 350 64cc Crate motor, 285/300hp, 72' or 90' center intake manifold bolt angels
14097088 89-date 502 2.19/1.88 118cc Replacement Rectangular port 325cc intake GEN V
14101081 87-95 305
14101083 87-up 350 64cc Gen.I, also used on crate motors, 285/300hp, 72' center manifold bolt ang
14101128 86-87 350 58cc Aluminum, angle plug
14101398 86-90 454 2.06/1.77 Open chamber Oval port
14102187 87-91 305 1.84/1.50
14102188 88- 93 350 centerbolt

17. Small Block Chevy Head Casting Numbers
Post link: https://angf35eis.com/sbc-head-casting-numbers/
Casting number Year C.I.D. Valves Chamber Size Notes
14102191 87-up 350
14102193 87-up 305/350 1.94/1.50
22542525 Aluminum, Dart/Olds/Chevy, 14' or 17' race head
24502559 96-97 38cc Aluminum, Bowtie, "SB2", 1st version, "mirror ports", 196cc intake ports,
24502585 Olds/Chevy DRCE 2 Pro Stock aluminum
25500141 2.1/1.625 42cc Aluminum, Buick/Chevy, 10' race head, symmetrical ports, 235cc intake p
33417369 90-up 350 76cc Gen.I Goodwrench crate motor, Hecho en Mexico
25534351C 04-up 2.00/1.55 65cc cast iron Vortec head, Gen.I Bowtie, 175/65cc ports, small port head
25534371C 04-up 2.00/1.55 77cc cast iron Vortec head, Gen.I Bowtie, 206/77cc ports, large port head
370r3523 55 265
3740r997 57 283 2x4 & FI (exc.-283hp)
3782461X 60-63 283/327 62cc Camel hump, no accessory holes, larger 172/64cc port volumes
3932441X 69-70 350/400 80cc
3947041X 69-70 302/350 64cc Right angle casting identifier, 165cc intake port, accessory holes, good H
3973487X 71-72 350
1.94/1.50;
2.02/1.60 75cc
3986336X 71 350 76cc
3986339X 71 307/350 74cc
10129552 1987-95 350 cc
3874480 1960-67 238/327 1.72/1.50 69cc
3890462, 3891462
1962-68 302/327/350
2.02/1.60;
1.94/1.50 63.3cc
Camel hump heads, no accessory holes
397041x 1969-70 1969-70 2.02/1.60 64cc right angle casting identifier.
3986339, and X 1968-79 307/350 1.72/1.50 74.5cc car, truck
398633x 350 1.94/1.50 76cc