SBC cylinder head identification
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| − | '''462''' is the most-used SBC head casting number out there- at least six different | + | '''462''' is the most-used SBC head casting number out there- at least six different SBC cylinder head casting numbers end in 462, according to 'the books': |
| + | [[File:462 double hump head.gif|left|frame|thumb|SBC cylinder head casting number 3990462, c/n 378461 similar.]] | ||
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• 3891462 | • 3891462 | ||
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| − | ==== | + | ====Diagrams of some common small block Chevy head ID castings==== |
| − | + | [[File:CastingMarkssbcheads.jpg]] | |
| − | + | <Gallery> | |
| − | + | File:041 sbc cast id.jpg|SBC casting number 3947041, "G" below. | |
| − | + | File:292 angle plug.gif|SBC angle plug "Turbo" casting number 340292. | |
| − | [[File: | + | </Gallery> |
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[[File:Sbc head casting id.jpg]] | [[File:Sbc head casting id.jpg]] | ||
*'''A-''' Rectangle c/n 460, 1955 & up 265/283, 8:1 CR, 1.72" x 1.50" valves. | *'''A-''' Rectangle c/n 460, 1955 & up 265/283, 8:1 CR, 1.72" x 1.50" valves. | ||
| − | *'''B-''' Narrow triangle over rectangle c/n 520, 896, 1958 and up 283 PowerPak and 1957-'60 | + | *'''B-''' Narrow triangle over rectangle c/n 520, 896, 1958 and up 283 PowerPak and 1957-'60 FI. 9.25:1 CR, 1.72" x 1.50" valves, 59cc nominal chamber volume. Could be used on a 305 but no accessory holes and has unhardened exhaust seats. |
| − | *'''C-''' Vertical bar over rectangle c/n 997, 1957 Corvette 270 HP, 9.5:1 CR, chamber similar to PowerPak but with sharp corners in plug | + | *'''C-''' Vertical bar over rectangle c/n 997, 1957 Corvette 270 HP, 9.5:1 CR, chamber similar to PowerPak but with sharp corners in plug area. |
*'''D-''' 2 vertical bars over rectangle, c/n 997, 1956 Corvette 2X4-bbl 283; 1958 passenger car FI; chamber same as 1957 270 HP Corvette. | *'''D-''' 2 vertical bars over rectangle, c/n 997, 1956 Corvette 2X4-bbl 283; 1958 passenger car FI; chamber same as 1957 270 HP Corvette. | ||
| − | *'''E''', '''F-''' Large “camel hump” c/n 291, 461, 461X, 462. | + | *'''E''', '''F-''' Large “camel hump” c/n 291, 461, 461X, 462. High performance or “fuelie” heads, chamber sizes are 62-64 cc nominal, came with either 1.94" x 1.50" or 2.02" x 1.60" valves, c/n 291 on 327 through 1968, has temperature gauge sender hole; 462 do not have temp sender hole. |
*'''G-''' Left-facing right triangle c/n 041, 1969-'70 350/300HP, accessory bolt holes, most have 1.94" x 1.50" valves | *'''G-''' Left-facing right triangle c/n 041, 1969-'70 350/300HP, accessory bolt holes, most have 1.94" x 1.50" valves | ||
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*'''P-''' Double (Captain’s) bars c/n 193. Used on TBI equipped engines. Mid-1980- up style centerbolt valve cover. Has restrictive vane cast in intake port to induce swirl/turbulence. Not usually recommended for high RPM performance applications unless serious port work is done. Hardened exhaust seats. | *'''P-''' Double (Captain’s) bars c/n 193. Used on TBI equipped engines. Mid-1980- up style centerbolt valve cover. Has restrictive vane cast in intake port to induce swirl/turbulence. Not usually recommended for high RPM performance applications unless serious port work is done. Hardened exhaust seats. | ||
| + | ====Vortec L30 5.0L heads==== | ||
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| + | ====Vortec L31 5.7L heads==== | ||
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| + | The L31 5.7L Vortec casting numbers are '''12559062''' and '''10239906'''. | ||
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| + | [[File:062_VORTEC_END_ID_001.jpg|left|frame|Casting number 12558062 head has 3 small humps, aka "sawtooth" on the end of the head.]][[File:906 VORTEC END ID.jpg|right|frame|Casting number 10239906 head has one large single hump on the end of the head.]] | ||
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| + | <Gallery> | ||
| + | File:Early chamber left vortec right.jpg|Early 64 cc chamber, left; L31 5.7L Vortec 64 cc chamber, right | ||
| + | File:Sbc swirl port chamber.jpg|SBC TBI swirl port 64 cc chamber. | ||
| + | </Gallery> | ||
| + | <br style="clear:both"/> | ||
====SBC heads to avoid==== | ====SBC heads to avoid==== | ||
| − | The c/n | + | The c/n 462624 is said to be very prone to cracking. Even though they can be found fitted with 2.02" x 1.60" valves and screw in studs/guide plates from the factory, they still are not a good choice for serious performance use. |
1971-up heads with casting numbers 882, 993, 487, 336 can have 3/8" exhaust stems as well as 1.72" intake valves. Heavy 20-30 Series truck use, mainly. Both small 1.72" intake and 3/8" stem exhaust valves may be found on c/n's 261, 624. Also 1987-'95 center bolt v-cover-type head # 14102191 can have the 3/8" exhaust valve. | 1971-up heads with casting numbers 882, 993, 487, 336 can have 3/8" exhaust stems as well as 1.72" intake valves. Heavy 20-30 Series truck use, mainly. Both small 1.72" intake and 3/8" stem exhaust valves may be found on c/n's 261, 624. Also 1987-'95 center bolt v-cover-type head # 14102191 can have the 3/8" exhaust valve. | ||
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