SBC cylinder head identification
From Crankshaft Coalition Wiki
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==Overview== | ==Overview== | ||
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*'''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 | ||
| − | *'''H-''' Small “camel hump” c/n 186, 492. Later high performance or “fuelie” heads, some c/n 186 (1969 and later) and all c/n 492 have accessory bolt holes. Either 1.94" x 1.50" or 2.02" x 1.60" valves, 64cc nominal chamber volume. 1970 LT-1/Z-28 use c/n | + | *'''H-''' Small “camel hump” c/n 186, 492. Later high performance or “fuelie” heads, some c/n 186 (1969 and later) and all c/n 492 have accessory bolt holes. Either 1.94" x 1.50" or 2.02" x 1.60" valves, 64cc nominal chamber volume. 1970 LT-1/Z-28 use c/n 186. |
*'''I-''' Large triangle over rectangle (“crown”) c/n 882. Large chamber (76 cc nominal), hardened exhaust valve seats, compromised intake port (1971-'76 350/400 cid). One of the most common smog heads, performance use is limited. | *'''I-''' Large triangle over rectangle (“crown”) c/n 882. Large chamber (76 cc nominal), hardened exhaust valve seats, compromised intake port (1971-'76 350/400 cid). One of the most common smog heads, performance use is limited. | ||
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*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/guideplates from the factory, they still are not a good choice for serious performance use. | *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/guideplates from the factory, they still are not a good choice for serious performance use. | ||
| − | *1971-up heads with casting numbers 882, 993, 487, 336 (and others) can have 3/8" exhaust stems as well as 1.72" intake valves. Heavy 20-30 Series truck uses these, mainly. Both small 1.72" intake and 3/8" stem exhaust valves may be found on c/n 261, 624. Also 1987-'95 center bolt valve cover-type head c/n 14102191 can also have the 3/8" exhaust valve stem. | + | *1971-up heads with casting numbers 882, 993, 487, 336 (and others) can have 3/8" exhaust stems as well as 1.72" intake valves. Heavy 20-30 Series truck uses these, mainly. Both small 1.72" intake and 3/8" stem exhaust valves may be found on c/n 261, 624. Also 1987-'95 center bolt valve cover-type head c/n 14102191 (76cc chambers and used with some 3/4 - 1 ton truck/van applications) can also have the 3/8" exhaust valve stem. |
| − | *Usually swirl port TBI SBC heads are not used in high performance applications because they run out of breath earlier than the | + | *Usually swirl port TBI SBC heads are not used in high performance applications because most builders do not have a clue on the flow specs. They also do no take into account that these heads produce gobs of low end torque. Although they run out of breath earlier than the Vortec heads, if paired with the proper cam these heads a monsters in the 1/4 mile. Some casting numbers for them are 187, 191, 193. Similar to the [http://www.crankshaftcoalition.com/wiki/Swirl_port_SBC_heads swirl port heads], but without the swirl-inducing vane are c/n 14102187 (5.0L), 14101083 (5.7L TPI) and 14096217 (5.0L). |
==Current head casting/part numbers, specs== | ==Current head casting/part numbers, specs== | ||
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